metricsd: Rename metrics to metricsd.

This makes the import path less confusing:
* metrics/metrics_library.h is imported from the exported headers.
* metricsd/* for includes by the metrics daemon itself.

BUG: 22879597
Change-Id: I9f44ea3a548cae39d4546fcd724e8007f6dd4bd0

64 files changed, 7684 insertions, 0 deletions

diff --git a/metricsd/MODULE_LICENSE_BSD b/metricsd/MODULE_LICENSE_BSD
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/metricsd/MODULE_LICENSE_BSD
diff --git a/metricsd/NOTICE b/metricsd/NOTICE
new file mode 100644
index 000000000..b9e779f92
--- /dev/null
+++ b/metricsd/NOTICE
@@ -0,0 +1,27 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/metricsd/OWNERS b/metricsd/OWNERS
new file mode 100644
index 000000000..7f5e50dab
--- /dev/null
+++ b/metricsd/OWNERS
@@ -0,0 +1,3 @@
+semenzato@chromium.org
+derat@chromium.org
+bsimonnet@chromium.org
diff --git a/metricsd/README b/metricsd/README
new file mode 100644
index 000000000..4b92af35f
--- /dev/null
+++ b/metricsd/README
@@ -0,0 +1,138 @@
+Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+Use of this source code is governed by a BSD-style license that can be
+found in the LICENSE file.
+
+The Chrome OS "metrics" package contains utilities for client-side user metric
+collection.
+When Chrome is installed, Chrome will take care of aggregating and uploading the
+metrics to the UMA server.
+When Chrome is not installed (embedded build) and the metrics_uploader USE flag
+is set, metrics_daemon will aggregate and upload the metrics itself.
+
+
+================================================================================
+The Metrics Library: libmetrics
+================================================================================
+
+libmetrics is a small library that implements the basic C and C++ API for
+metrics collection. All metrics collection is funneled through this library. The
+easiest and recommended way for a client-side module to collect user metrics is
+to link libmetrics and use its APIs to send metrics to Chrome for transport to
+UMA. In order to use the library in a module, you need to do the following:
+
+- Add a dependence (DEPEND and RDEPEND) on chromeos-base/metrics to the module's
+  ebuild.
+
+- Link the module with libmetrics (for example, by passing -lmetrics to the
+  module's link command). Both libmetrics.so and libmetrics.a are built and
+  installed under $SYSROOT/usr/lib/. Note that by default -lmetrics will link
+  against libmetrics.so, which is preferred.
+
+- To access the metrics library API in the module, include the
+  <metrics/metrics_library.h> header file. The file is installed in
+  $SYSROOT/usr/include/ when the metrics library is built and installed.
+
+- The API is documented in metrics_library.h under src/platform/metrics/. Before
+  using the API methods, a MetricsLibrary object needs to be constructed and
+  initialized through its Init method.
+
+  For more information on the C API see c_metrics_library.h.
+
+- Samples are sent to Chrome only if the "/home/chronos/Consent To Send Stats"
+  file exists or the metrics are declared enabled in the policy file (see the
+  AreMetricsEnabled API method).
+
+- On the target platform, shortly after the sample is sent, it should be visible
+  in Chrome through "about:histograms".
+
+
+================================================================================
+Histogram Naming Convention
+================================================================================
+
+Use TrackerArea.MetricName. For example:
+
+Platform.DailyUseTime
+Network.TimeToDrop
+
+
+================================================================================
+Server Side
+================================================================================
+
+If the histogram data is visible in about:histograms, it will be sent by an
+official Chrome build to UMA, assuming the user has opted into metrics
+collection. To make the histogram visible on "chromedashboard", the histogram
+description XML file needs to be updated (steps 2 and 3 after following the
+"Details on how to add your own histograms" link under the Histograms tab).
+Include the string "Chrome OS" in the histogram description so that it's easier
+to distinguish Chrome OS specific metrics from general Chrome histograms.
+
+The UMA server logs and keeps the collected field data even if the metric's name
+is not added to the histogram XML. However, the dashboard histogram for that
+metric will show field data as of the histogram XML update date; it will not
+include data for older dates. If past data needs to be displayed, manual
+server-side intervention is required. In other words, one should assume that
+field data collection starts only after the histogram XML has been updated.
+
+
+================================================================================
+The Metrics Client: metrics_client
+================================================================================
+
+metrics_client is a simple shell command-line utility for sending histogram
+samples and user actions. It's installed under /usr/bin on the target platform
+and uses libmetrics to send the data to Chrome. The utility is useful for
+generating metrics from shell scripts.
+
+For usage information and command-line options, run "metrics_client" on the
+target platform or look for "Usage:" in metrics_client.cc.
+
+
+================================================================================
+The Metrics Daemon: metrics_daemon
+================================================================================
+
+metrics_daemon is a daemon that runs in the background on the target platform
+and is intended for passive or ongoing metrics collection, or metrics collection
+requiring feedback from multiple modules. For example, it listens to D-Bus
+signals related to the user session and screen saver states to determine if the
+user is actively using the device or not and generates the corresponding
+data. The metrics daemon uses libmetrics to send the data to Chrome.
+
+The recommended way to generate metrics data from a module is to link and use
+libmetrics directly. However, the module could instead send signals to or
+communicate in some alternative way with the metrics daemon. Then the metrics
+daemon needs to monitor for the relevant events and take appropriate action --
+for example, aggregate data and send the histogram samples.
+
+
+================================================================================
+FAQ
+================================================================================
+
+Q. What should my histogram's |min| and |max| values be set at?
+
+A. You should set the values to a range that covers the vast majority of samples
+   that would appear in the field. Note that samples below the |min| will still
+   be collected in the underflow bucket and samples above the |max| will end up
+   in the overflow bucket. Also, the reported mean of the data will be correct
+   regardless of the range.
+
+Q. How many buckets should I use in my histogram?
+
+A. You should allocate as many buckets as necessary to perform proper analysis
+   on the collected data. Note, however, that the memory allocated in Chrome for
+   each histogram is proportional to the number of buckets. Therefore, it is
+   strongly recommended to keep this number low (e.g., 50 is normal, while 100
+   is probably high).
+
+Q. When should I use an enumeration (linear) histogram vs. a regular
+   (exponential) histogram?
+
+A. Enumeration histograms should really be used only for sampling enumerated
+   events and, in some cases, percentages. Normally, you should use a regular
+   histogram with exponential bucket layout that provides higher resolution at
+   the low end of the range and lower resolution at the high end. Regular
+   histograms are generally used for collecting performance data (e.g., timing,
+   memory usage, power) as well as aggregated event counts.
diff --git a/metricsd/WATCHLISTS b/metricsd/WATCHLISTS
new file mode 100644
index 000000000..a051f350f
--- /dev/null
+++ b/metricsd/WATCHLISTS
@@ -0,0 +1,16 @@
+# See http://dev.chromium.org/developers/contributing-code/watchlists for
+# a description of this file's format.
+# Please keep these keys in alphabetical order.
+
+{
+  'WATCHLIST_DEFINITIONS': {
+    'all': {
+      'filepath': '.',
+    },
+  },
+  'WATCHLISTS': {
+    'all': ['petkov@chromium.org',
+                'semenzato@chromium.org',
+                'sosa@chromium.org']
+  },
+}
diff --git a/metricsd/c_metrics_library.cc b/metricsd/c_metrics_library.cc
new file mode 100644
index 000000000..90a2d59c9
--- /dev/null
+++ b/metricsd/c_metrics_library.cc
@@ -0,0 +1,78 @@
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+//
+// C wrapper to libmetrics
+//
+
+#include "metrics/c_metrics_library.h"
+
+#include <string>
+
+#include "metrics/metrics_library.h"
+
+extern "C" CMetricsLibrary CMetricsLibraryNew(void) {
+  MetricsLibrary* lib = new MetricsLibrary;
+  return reinterpret_cast<CMetricsLibrary>(lib);
+}
+
+extern "C" void CMetricsLibraryDelete(CMetricsLibrary handle) {
+  MetricsLibrary* lib = reinterpret_cast<MetricsLibrary*>(handle);
+  delete lib;
+}
+
+extern "C" void CMetricsLibraryInit(CMetricsLibrary handle) {
+  MetricsLibrary* lib = reinterpret_cast<MetricsLibrary*>(handle);
+  if (lib != NULL)
+    lib->Init();
+}
+
+extern "C" int CMetricsLibrarySendToUMA(CMetricsLibrary handle,
+                                        const char* name, int sample,
+                                        int min, int max, int nbuckets) {
+  MetricsLibrary* lib = reinterpret_cast<MetricsLibrary*>(handle);
+  if (lib == NULL)
+    return 0;
+  return lib->SendToUMA(std::string(name), sample, min, max, nbuckets);
+}
+
+extern "C" int CMetricsLibrarySendEnumToUMA(CMetricsLibrary handle,
+                                            const char* name, int sample,
+                                            int max) {
+  MetricsLibrary* lib = reinterpret_cast<MetricsLibrary*>(handle);
+  if (lib == NULL)
+    return 0;
+  return lib->SendEnumToUMA(std::string(name), sample, max);
+}
+
+extern "C" int CMetricsLibrarySendSparseToUMA(CMetricsLibrary handle,
+                                              const char* name, int sample) {
+  MetricsLibrary* lib = reinterpret_cast<MetricsLibrary*>(handle);
+  if (lib == NULL)
+    return 0;
+  return lib->SendSparseToUMA(std::string(name), sample);
+}
+
+extern "C" int CMetricsLibrarySendUserActionToUMA(CMetricsLibrary handle,
+                                                  const char* action) {
+  MetricsLibrary* lib = reinterpret_cast<MetricsLibrary*>(handle);
+  if (lib == NULL)
+    return 0;
+  return lib->SendUserActionToUMA(std::string(action));
+}
+
+extern "C" int CMetricsLibrarySendCrashToUMA(CMetricsLibrary handle,
+                                            const char* crash_kind) {
+  MetricsLibrary* lib = reinterpret_cast<MetricsLibrary*>(handle);
+  if (lib == NULL)
+    return 0;
+  return lib->SendCrashToUMA(crash_kind);
+}
+
+extern "C" int CMetricsLibraryAreMetricsEnabled(CMetricsLibrary handle) {
+  MetricsLibrary* lib = reinterpret_cast<MetricsLibrary*>(handle);
+  if (lib == NULL)
+    return 0;
+  return lib->AreMetricsEnabled();
+}
diff --git a/metricsd/constants.h b/metricsd/constants.h
new file mode 100644
index 000000000..d65e0e0cc
--- /dev/null
+++ b/metricsd/constants.h
@@ -0,0 +1,29 @@
+//
+// Copyright (C) 2015 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#ifndef METRICS_CONSTANTS_H_
+#define METRICS_CONSTANTS_H_
+
+namespace metrics {
+static const char kMetricsDirectory[] = "/data/misc/metrics/";
+static const char kMetricsEventsFilePath[] = "/data/misc/metrics/uma-events";
+static const char kMetricsGUIDFilePath[] = "/data/misc/metrics/Sysinfo.GUID";
+static const char kMetricsServer[] = "http://clients4.google.com/uma/v2";
+static const char kConsentFilePath[] = "/data/misc/metrics/enabled";
+static const char kDefaultVersion[] = "0.0.0.0";
+}  // namespace metrics
+
+#endif  // METRICS_CONSTANTS_H_
diff --git a/metricsd/include/metrics/c_metrics_library.h b/metricsd/include/metrics/c_metrics_library.h
new file mode 100644
index 000000000..7f78e43a7
--- /dev/null
+++ b/metricsd/include/metrics/c_metrics_library.h
@@ -0,0 +1,49 @@
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_C_METRICS_LIBRARY_H_
+#define METRICS_C_METRICS_LIBRARY_H_
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+typedef struct CMetricsLibraryOpaque* CMetricsLibrary;
+
+// C wrapper for MetricsLibrary::MetricsLibrary.
+CMetricsLibrary CMetricsLibraryNew(void);
+
+// C wrapper for MetricsLibrary::~MetricsLibrary.
+void CMetricsLibraryDelete(CMetricsLibrary handle);
+
+// C wrapper for MetricsLibrary::Init.
+void CMetricsLibraryInit(CMetricsLibrary handle);
+
+// C wrapper for MetricsLibrary::SendToUMA.
+int CMetricsLibrarySendToUMA(CMetricsLibrary handle,
+                             const char* name, int sample,
+                             int min, int max, int nbuckets);
+
+// C wrapper for MetricsLibrary::SendEnumToUMA.
+int CMetricsLibrarySendEnumToUMA(CMetricsLibrary handle,
+                                 const char* name, int sample, int max);
+
+// C wrapper for MetricsLibrary::SendSparseToUMA.
+int CMetricsLibrarySendSparseToUMA(CMetricsLibrary handle,
+                                   const char* name, int sample);
+
+// C wrapper for MetricsLibrary::SendUserActionToUMA.
+int CMetricsLibrarySendUserActionToUMA(CMetricsLibrary handle,
+                                       const char* action);
+
+// C wrapper for MetricsLibrary::SendCrashToUMA.
+int CMetricsLibrarySendCrashToUMA(CMetricsLibrary handle,
+                                  const char* crash_kind);
+
+// C wrapper for MetricsLibrary::AreMetricsEnabled.
+int CMetricsLibraryAreMetricsEnabled(CMetricsLibrary handle);
+
+#if defined(__cplusplus)
+}
+#endif
+#endif  // METRICS_C_METRICS_LIBRARY_H_
diff --git a/metricsd/include/metrics/metrics_library.h b/metricsd/include/metrics/metrics_library.h
new file mode 100644
index 000000000..1c124d2ae
--- /dev/null
+++ b/metricsd/include/metrics/metrics_library.h
@@ -0,0 +1,140 @@
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_METRICS_LIBRARY_H_
+#define METRICS_METRICS_LIBRARY_H_
+
+#include <sys/types.h>
+#include <string>
+#include <unistd.h>
+
+#include <base/compiler_specific.h>
+#include <base/macros.h>
+#include <base/memory/scoped_ptr.h>
+#include <gtest/gtest_prod.h>  // for FRIEND_TEST
+
+class MetricsLibraryInterface {
+ public:
+  virtual void Init() = 0;
+  virtual bool AreMetricsEnabled() = 0;
+  virtual bool SendToUMA(const std::string& name, int sample,
+                         int min, int max, int nbuckets) = 0;
+  virtual bool SendEnumToUMA(const std::string& name, int sample, int max) = 0;
+  virtual bool SendSparseToUMA(const std::string& name, int sample) = 0;
+  virtual bool SendUserActionToUMA(const std::string& action) = 0;
+  virtual ~MetricsLibraryInterface() {}
+};
+
+// Library used to send metrics to Chrome/UMA.
+class MetricsLibrary : public MetricsLibraryInterface {
+ public:
+  MetricsLibrary();
+  virtual ~MetricsLibrary();
+
+  // Initializes the library.
+  void Init() override;
+
+  // Returns whether or not the machine is running in guest mode.
+  bool IsGuestMode();
+
+  // Returns whether or not metrics collection is enabled.
+  bool AreMetricsEnabled() override;
+
+  // Sends histogram data to Chrome for transport to UMA and returns
+  // true on success. This method results in the equivalent of an
+  // asynchronous non-blocking RPC to UMA_HISTOGRAM_CUSTOM_COUNTS
+  // inside Chrome (see base/histogram.h).
+  //
+  // |sample| is the sample value to be recorded (|min| <= |sample| < |max|).
+  // |min| is the minimum value of the histogram samples (|min| > 0).
+  // |max| is the maximum value of the histogram samples.
+  // |nbuckets| is the number of histogram buckets.
+  // [0,min) is the implicit underflow bucket.
+  // [|max|,infinity) is the implicit overflow bucket.
+  //
+  // Note that the memory allocated in Chrome for each histogram is
+  // proportional to the number of buckets. Therefore, it is strongly
+  // recommended to keep this number low (e.g., 50 is normal, while
+  // 100 is high).
+  bool SendToUMA(const std::string& name, int sample,
+                 int min, int max, int nbuckets) override;
+
+  // Sends linear histogram data to Chrome for transport to UMA and
+  // returns true on success. This method results in the equivalent of
+  // an asynchronous non-blocking RPC to UMA_HISTOGRAM_ENUMERATION
+  // inside Chrome (see base/histogram.h).
+  //
+  // |sample| is the sample value to be recorded (1 <= |sample| < |max|).
+  // |max| is the maximum value of the histogram samples.
+  // 0 is the implicit underflow bucket.
+  // [|max|,infinity) is the implicit overflow bucket.
+  //
+  // An enumeration histogram requires |max| + 1 number of
+  // buckets. Note that the memory allocated in Chrome for each
+  // histogram is proportional to the number of buckets. Therefore, it
+  // is strongly recommended to keep this number low (e.g., 50 is
+  // normal, while 100 is high).
+  bool SendEnumToUMA(const std::string& name, int sample, int max) override;
+
+  // Sends sparse histogram sample to Chrome for transport to UMA.  Returns
+  // true on success.
+  //
+  // |sample| is the 32-bit integer value to be recorded.
+  bool SendSparseToUMA(const std::string& name, int sample) override;
+
+  // Sends a user action to Chrome for transport to UMA and returns true on
+  // success. This method results in the equivalent of an asynchronous
+  // non-blocking RPC to UserMetrics::RecordAction.  The new metric must be
+  // added to chrome/tools/extract_actions.py in the Chromium repository, which
+  // should then be run to generate a hash for the new action.
+  //
+  // Until http://crosbug.com/11125 is fixed, the metric must also be added to
+  // chrome/browser/chromeos/external_metrics.cc.
+  //
+  // |action| is the user-generated event (e.g., "MuteKeyPressed").
+  bool SendUserActionToUMA(const std::string& action) override;
+
+  // Sends a signal to UMA that a crash of the given |crash_kind|
+  // has occurred.  Used by UMA to generate stability statistics.
+  bool SendCrashToUMA(const char *crash_kind);
+
+  // Sends a "generic Chrome OS event" to UMA.  This is an event name
+  // that is translated into an enumerated histogram entry.  Event names
+  // are added to metrics_library.cc.  Optionally, they can be added
+  // to histograms.xml---but part of the reason for this is to simplify
+  // the addition of events (at the cost of having to look them up by
+  // number in the histograms dashboard).
+  bool SendCrosEventToUMA(const std::string& event);
+
+ private:
+  friend class CMetricsLibraryTest;
+  friend class MetricsLibraryTest;
+  FRIEND_TEST(MetricsLibraryTest, AreMetricsEnabled);
+  FRIEND_TEST(MetricsLibraryTest, FormatChromeMessage);
+  FRIEND_TEST(MetricsLibraryTest, FormatChromeMessageTooLong);
+  FRIEND_TEST(MetricsLibraryTest, IsDeviceMounted);
+  FRIEND_TEST(MetricsLibraryTest, SendMessageToChrome);
+  FRIEND_TEST(MetricsLibraryTest, SendMessageToChromeUMAEventsBadFileLocation);
+
+  // Sets |*result| to whether or not the |mounts_file| indicates that
+  // the |device_name| is currently mounted.  Uses |buffer| of
+  // |buffer_size| to read the file.  Returns false if any error.
+  bool IsDeviceMounted(const char* device_name,
+                       const char* mounts_file,
+                       char* buffer, int buffer_size,
+                       bool* result);
+
+  // Time at which we last checked if metrics were enabled.
+  static time_t cached_enabled_time_;
+
+  // Cached state of whether or not metrics were enabled.
+  static bool cached_enabled_;
+
+  std::string uma_events_file_;
+  std::string consent_file_;
+
+  DISALLOW_COPY_AND_ASSIGN(MetricsLibrary);
+};
+
+#endif  // METRICS_METRICS_LIBRARY_H_
diff --git a/metricsd/init/metrics_daemon.conf b/metricsd/init/metrics_daemon.conf
new file mode 100644
index 000000000..e6932cf99
--- /dev/null
+++ b/metricsd/init/metrics_daemon.conf
@@ -0,0 +1,18 @@
+# Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+description     "Metrics collection daemon"
+author          "chromium-os-dev@chromium.org"
+
+# The metrics daemon is responsible for receiving and forwarding to
+# chrome UMA statistics not produced by chrome.
+start on starting system-services
+stop on stopping system-services
+respawn
+
+# metrics will update the next line to add -uploader for embedded builds.
+env DAEMON_FLAGS=""
+
+expect fork
+exec metrics_daemon ${DAEMON_FLAGS}
diff --git a/metricsd/init/metrics_library.conf b/metricsd/init/metrics_library.conf
new file mode 100644
index 000000000..03016d129
--- /dev/null
+++ b/metricsd/init/metrics_library.conf
@@ -0,0 +1,25 @@
+# Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+description     "Metrics Library upstart file"
+author          "chromium-os-dev@chromium.org"
+
+# The metrics library is used by several programs (daemons and others)
+# to send UMA stats.
+start on starting boot-services
+
+pre-start script
+  # Create the file used as communication endpoint for metrics.
+  METRICS_DIR=/var/lib/metrics
+  EVENTS_FILE=${METRICS_DIR}/uma-events
+  mkdir -p ${METRICS_DIR}
+  touch ${EVENTS_FILE}
+  chown chronos.chronos ${EVENTS_FILE}
+  chmod 666 ${EVENTS_FILE}
+  # TRANSITION ONLY.
+  # TODO(semenzato) Remove after Chrome change, see issue 447256.
+  # Let Chrome read the metrics file from the old location.
+  mkdir -p /var/run/metrics
+  ln -sf ${EVENTS_FILE} /var/run/metrics
+end script
diff --git a/metricsd/libmetrics-334380.gyp b/metricsd/libmetrics-334380.gyp
new file mode 100644
index 000000000..9771821fb
--- /dev/null
+++ b/metricsd/libmetrics-334380.gyp
@@ -0,0 +1,8 @@
+{
+  'variables': {
+    'libbase_ver': 334380,
+  },
+  'includes': [
+    'libmetrics.gypi',
+  ],
+}
diff --git a/metricsd/libmetrics.gypi b/metricsd/libmetrics.gypi
new file mode 100644
index 000000000..5b90a550c
--- /dev/null
+++ b/metricsd/libmetrics.gypi
@@ -0,0 +1,33 @@
+{
+  'target_defaults': {
+    'variables': {
+      'deps': [
+        'libchrome-<(libbase_ver)',
+        'libchromeos-<(libbase_ver)',
+      ]
+    },
+    'cflags_cc': [
+      '-fno-exceptions',
+    ],
+  },
+  'targets': [
+    {
+      'target_name': 'libmetrics-<(libbase_ver)',
+      'type': 'shared_library',
+      'cflags': [
+        '-fvisibility=default',
+      ],
+      'libraries+': [
+        '-lpolicy-<(libbase_ver)',
+      ],
+      'sources': [
+        'c_metrics_library.cc',
+        'metrics_library.cc',
+        'serialization/metric_sample.cc',
+        'serialization/serialization_utils.cc',
+        'timer.cc',
+      ],
+      'include_dirs': ['.'],
+    },
+  ],
+}
diff --git a/metricsd/libmetrics.pc.in b/metricsd/libmetrics.pc.in
new file mode 100644
index 000000000..233f3181a
--- /dev/null
+++ b/metricsd/libmetrics.pc.in
@@ -0,0 +1,7 @@
+bslot=@BSLOT@
+
+Name: libmetrics
+Description: Chrome OS metrics library
+Version: ${bslot}
+Requires.private: libchrome-${bslot}
+Libs: -lmetrics-${bslot}
diff --git a/metricsd/make_tests.sh b/metricsd/make_tests.sh
new file mode 100755
index 000000000..9dcc80475
--- /dev/null
+++ b/metricsd/make_tests.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+
+# Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# Builds tests.
+
+set -e
+make tests
+mkdir -p "${OUT_DIR}"
+cp *_test "${OUT_DIR}"
diff --git a/metricsd/metrics.gyp b/metricsd/metrics.gyp
new file mode 100644
index 000000000..276ec7876
--- /dev/null
+++ b/metricsd/metrics.gyp
@@ -0,0 +1,184 @@
+{
+  'target_defaults': {
+    'variables': {
+      'deps': [
+        'dbus-1',
+        'libchrome-<(libbase_ver)',
+        'libchromeos-<(libbase_ver)',
+      ]
+    },
+    'cflags_cc': [
+      '-fno-exceptions',
+    ],
+  },
+  'targets': [
+    {
+      'target_name': 'libmetrics_daemon',
+      'type': 'static_library',
+      'dependencies': [
+        '../metrics/libmetrics-<(libbase_ver).gyp:libmetrics-<(libbase_ver)',
+        'libupload_service',
+        'metrics_proto',
+      ],
+      'link_settings': {
+        'libraries': [
+          '-lrootdev',
+        ],
+      },
+      'sources': [
+        'persistent_integer.cc',
+        'metrics_daemon.cc',
+        'metrics_daemon_main.cc',
+      ],
+      'include_dirs': ['.'],
+    },
+    {
+      'target_name': 'metrics_client',
+      'type': 'executable',
+      'dependencies': [
+        '../metrics/libmetrics-<(libbase_ver).gyp:libmetrics-<(libbase_ver)',
+      ],
+      'sources': [
+        'metrics_client.cc',
+      ]
+    },
+    {
+      'target_name': 'libupload_service',
+      'type': 'static_library',
+      'dependencies': [
+        'metrics_proto',
+        '../metrics/libmetrics-<(libbase_ver).gyp:libmetrics-<(libbase_ver)',
+      ],
+      'link_settings': {
+        'libraries': [
+          '-lvboot_host',
+        ],
+      },
+      'variables': {
+        'exported_deps': [
+          'protobuf-lite',
+        ],
+        'deps': [
+          '<@(exported_deps)',
+        ],
+      },
+      'all_dependent_settings': {
+        'variables': {
+          'deps+': [
+            '<@(exported_deps)',
+          ],
+        },
+      },
+      'sources': [
+        'uploader/upload_service.cc',
+        'uploader/metrics_hashes.cc',
+        'uploader/metrics_log.cc',
+        'uploader/metrics_log_base.cc',
+        'uploader/system_profile_cache.cc',
+        'uploader/sender_http.cc',
+      ],
+      'include_dirs': ['.']
+    },
+    {
+      'target_name': 'metrics_proto',
+      'type': 'static_library',
+      'variables': {
+        'proto_in_dir': 'uploader/proto',
+        'proto_out_dir': 'include/metrics/uploader/proto',
+      },
+      'sources': [
+        '<(proto_in_dir)/chrome_user_metrics_extension.proto',
+        '<(proto_in_dir)/histogram_event.proto',
+        '<(proto_in_dir)/system_profile.proto',
+        '<(proto_in_dir)/user_action_event.proto',
+      ],
+      'includes': [
+        '../common-mk/protoc.gypi'
+      ],
+    },
+  ],
+  'conditions': [
+    ['USE_passive_metrics == 1', {
+      'targets': [
+        {
+          'target_name': 'metrics_daemon',
+          'type': 'executable',
+          'dependencies': ['libmetrics_daemon'],
+        },
+      ],
+    }],
+    ['USE_test == 1', {
+      'targets': [
+        {
+          'target_name': 'persistent_integer_test',
+          'type': 'executable',
+          'includes': ['../common-mk/common_test.gypi'],
+          'sources': [
+            'persistent_integer.cc',
+            'persistent_integer_test.cc',
+          ]
+        },
+        {
+          'target_name': 'metrics_library_test',
+          'type': 'executable',
+          'dependencies': [
+            '../metrics/libmetrics-<(libbase_ver).gyp:libmetrics-<(libbase_ver)',
+          ],
+          'includes': ['../common-mk/common_test.gypi'],
+          'sources': [
+            'metrics_library_test.cc',
+            'serialization/serialization_utils_unittest.cc',
+          ],
+          'link_settings': {
+            'libraries': [
+              '-lpolicy-<(libbase_ver)',
+            ]
+          }
+        },
+        {
+          'target_name': 'timer_test',
+          'type': 'executable',
+          'includes': ['../common-mk/common_test.gypi'],
+          'sources': [
+            'timer.cc',
+            'timer_test.cc',
+          ]
+        },
+        {
+          'target_name': 'upload_service_test',
+          'type': 'executable',
+          'sources': [
+            'persistent_integer.cc',
+            'uploader/metrics_hashes_unittest.cc',
+            'uploader/metrics_log_base_unittest.cc',
+            'uploader/mock/sender_mock.cc',
+            'uploader/upload_service_test.cc',
+          ],
+          'dependencies': [
+            'libupload_service',
+          ],
+          'includes':[
+            '../common-mk/common_test.gypi',
+          ],
+          'include_dirs': ['.']
+        },
+      ],
+    }],
+    ['USE_passive_metrics == 1 and USE_test == 1', {
+      'targets': [
+        {
+          'target_name': 'metrics_daemon_test',
+          'type': 'executable',
+          'dependencies': [
+            'libmetrics_daemon',
+          ],
+          'includes': ['../common-mk/common_test.gypi'],
+          'sources': [
+            'metrics_daemon_test.cc',
+          ],
+          'include_dirs': ['.'],
+        },
+      ],
+    }],
+  ]
+}
diff --git a/metricsd/metrics_client.cc b/metricsd/metrics_client.cc
new file mode 100644
index 000000000..b587e3a24
--- /dev/null
+++ b/metricsd/metrics_client.cc
@@ -0,0 +1,198 @@
+// Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <cstdio>
+#include <cstdlib>
+
+#include "metrics/metrics_library.h"
+
+enum Mode {
+    kModeSendSample,
+    kModeSendEnumSample,
+    kModeSendSparseSample,
+    kModeSendUserAction,
+    kModeSendCrosEvent,
+    kModeHasConsent,
+    kModeIsGuestMode,
+};
+
+void ShowUsage() {
+  fprintf(stderr,
+          "Usage:  metrics_client [-t] name sample min max nbuckets\n"
+          "        metrics_client -e   name sample max\n"
+          "        metrics_client -s   name sample\n"
+          "        metrics_client -v   event\n"
+          "        metrics_client -u action\n"
+          "        metrics_client [-cg]\n"
+          "\n"
+          "  default: send metric with integer values \n"
+          "           |min| > 0, |min| <= sample < |max|\n"
+          "  -c: return exit status 0 if user consents to stats, 1 otherwise,\n"
+          "      in guest mode always return 1\n"
+          "  -e: send linear/enumeration histogram data\n"
+          "  -g: return exit status 0 if machine in guest mode, 1 otherwise\n"
+          "  -s: send a sparse histogram sample\n"
+          "  -t: convert sample from double seconds to int milliseconds\n"
+          "  -u: send a user action to Chrome\n"
+          "  -v: send a Platform.CrOSEvent enum histogram sample\n");
+  exit(1);
+}
+
+static int ParseInt(const char *arg) {
+  char *endptr;
+  int value = strtol(arg, &endptr, 0);
+  if (*endptr != '\0') {
+    fprintf(stderr, "metrics client: bad integer \"%s\"\n", arg);
+    ShowUsage();
+  }
+  return value;
+}
+
+static double ParseDouble(const char *arg) {
+  char *endptr;
+  double value = strtod(arg, &endptr);
+  if (*endptr != '\0') {
+    fprintf(stderr, "metrics client: bad double \"%s\"\n", arg);
+    ShowUsage();
+  }
+  return value;
+}
+
+static int SendStats(char* argv[],
+                     int name_index,
+                     enum Mode mode,
+                     bool secs_to_msecs) {
+  const char* name = argv[name_index];
+  int sample;
+  if (secs_to_msecs) {
+    sample = static_cast<int>(ParseDouble(argv[name_index + 1]) * 1000.0);
+  } else {
+    sample = ParseInt(argv[name_index + 1]);
+  }
+
+  MetricsLibrary metrics_lib;
+  metrics_lib.Init();
+  if (mode == kModeSendSparseSample) {
+    metrics_lib.SendSparseToUMA(name, sample);
+  } else if (mode == kModeSendEnumSample) {
+    int max = ParseInt(argv[name_index + 2]);
+    metrics_lib.SendEnumToUMA(name, sample, max);
+  } else {
+    int min = ParseInt(argv[name_index + 2]);
+    int max = ParseInt(argv[name_index + 3]);
+    int nbuckets = ParseInt(argv[name_index + 4]);
+    metrics_lib.SendToUMA(name, sample, min, max, nbuckets);
+  }
+  return 0;
+}
+
+static int SendUserAction(char* argv[], int action_index) {
+  const char* action = argv[action_index];
+  MetricsLibrary metrics_lib;
+  metrics_lib.Init();
+  metrics_lib.SendUserActionToUMA(action);
+  return 0;
+}
+
+static int SendCrosEvent(char* argv[], int action_index) {
+  const char* event = argv[action_index];
+  bool result;
+  MetricsLibrary metrics_lib;
+  metrics_lib.Init();
+  result = metrics_lib.SendCrosEventToUMA(event);
+  if (!result) {
+    fprintf(stderr, "metrics_client: could not send event %s\n", event);
+    return 1;
+  }
+  return 0;
+}
+
+static int HasConsent() {
+  MetricsLibrary metrics_lib;
+  metrics_lib.Init();
+  return metrics_lib.AreMetricsEnabled() ? 0 : 1;
+}
+
+static int IsGuestMode() {
+  MetricsLibrary metrics_lib;
+  metrics_lib.Init();
+  return metrics_lib.IsGuestMode() ? 0 : 1;
+}
+
+int main(int argc, char** argv) {
+  enum Mode mode = kModeSendSample;
+  bool secs_to_msecs = false;
+
+  // Parse arguments
+  int flag;
+  while ((flag = getopt(argc, argv, "abcegstuv")) != -1) {
+    switch (flag) {
+      case 'c':
+        mode = kModeHasConsent;
+        break;
+      case 'e':
+        mode = kModeSendEnumSample;
+        break;
+      case 'g':
+        mode = kModeIsGuestMode;
+        break;
+      case 's':
+        mode = kModeSendSparseSample;
+        break;
+      case 't':
+        secs_to_msecs = true;
+        break;
+      case 'u':
+        mode = kModeSendUserAction;
+        break;
+      case 'v':
+        mode = kModeSendCrosEvent;
+        break;
+      default:
+        ShowUsage();
+        break;
+    }
+  }
+  int arg_index = optind;
+
+  int expected_args = 0;
+  if (mode == kModeSendSample)
+    expected_args = 5;
+  else if (mode == kModeSendEnumSample)
+    expected_args = 3;
+  else if (mode == kModeSendSparseSample)
+    expected_args = 2;
+  else if (mode == kModeSendUserAction)
+    expected_args = 1;
+  else if (mode == kModeSendCrosEvent)
+    expected_args = 1;
+
+  if ((arg_index + expected_args) != argc) {
+    ShowUsage();
+  }
+
+  switch (mode) {
+    case kModeSendSample:
+    case kModeSendEnumSample:
+    case kModeSendSparseSample:
+      if ((mode != kModeSendSample) && secs_to_msecs) {
+        ShowUsage();
+      }
+      return SendStats(argv,
+                       arg_index,
+                       mode,
+                       secs_to_msecs);
+    case kModeSendUserAction:
+      return SendUserAction(argv, arg_index);
+    case kModeSendCrosEvent:
+      return SendCrosEvent(argv, arg_index);
+    case kModeHasConsent:
+      return HasConsent();
+    case kModeIsGuestMode:
+      return IsGuestMode();
+    default:
+      ShowUsage();
+      return 0;
+  }
+}
diff --git a/metricsd/metrics_daemon.cc b/metricsd/metrics_daemon.cc
new file mode 100644
index 000000000..f9061d563
--- /dev/null
+++ b/metricsd/metrics_daemon.cc
@@ -0,0 +1,1105 @@
+// Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "metrics_daemon.h"
+
+#include <fcntl.h>
+#include <inttypes.h>
+#include <math.h>
+#include <string.h>
+#include <sysexits.h>
+#include <time.h>
+
+#include <base/bind.h>
+#include <base/files/file_path.h>
+#include <base/files/file_util.h>
+#include <base/hash.h>
+#include <base/logging.h>
+#include <base/strings/string_number_conversions.h>
+#include <base/strings/string_split.h>
+#include <base/strings/string_util.h>
+#include <base/strings/stringprintf.h>
+#include <base/sys_info.h>
+#include <dbus/dbus.h>
+#include <dbus/message.h>
+
+#include "constants.h"
+#include "uploader/upload_service.h"
+
+using base::FilePath;
+using base::StringPrintf;
+using base::Time;
+using base::TimeDelta;
+using base::TimeTicks;
+using chromeos_metrics::PersistentInteger;
+using std::map;
+using std::string;
+using std::vector;
+
+namespace {
+
+#define SAFE_MESSAGE(e) (e.message ? e.message : "unknown error")
+
+const char kCrashReporterInterface[] = "org.chromium.CrashReporter";
+const char kCrashReporterUserCrashSignal[] = "UserCrash";
+const char kCrashReporterMatchRule[] =
+    "type='signal',interface='%s',path='/',member='%s'";
+
+const int kSecondsPerMinute = 60;
+const int kMinutesPerHour = 60;
+const int kHoursPerDay = 24;
+const int kMinutesPerDay = kHoursPerDay * kMinutesPerHour;
+const int kSecondsPerDay = kSecondsPerMinute * kMinutesPerDay;
+const int kDaysPerWeek = 7;
+const int kSecondsPerWeek = kSecondsPerDay * kDaysPerWeek;
+
+// Interval between calls to UpdateStats().
+const uint32_t kUpdateStatsIntervalMs = 300000;
+
+const char kKernelCrashDetectedFile[] = "/var/run/kernel-crash-detected";
+const char kUncleanShutdownDetectedFile[] =
+    "/var/run/unclean-shutdown-detected";
+
+}  // namespace
+
+// disk stats metrics
+
+// The {Read,Write}Sectors numbers are in sectors/second.
+// A sector is usually 512 bytes.
+
+const char MetricsDaemon::kMetricReadSectorsLongName[] =
+    "Platform.ReadSectorsLong";
+const char MetricsDaemon::kMetricWriteSectorsLongName[] =
+    "Platform.WriteSectorsLong";
+const char MetricsDaemon::kMetricReadSectorsShortName[] =
+    "Platform.ReadSectorsShort";
+const char MetricsDaemon::kMetricWriteSectorsShortName[] =
+    "Platform.WriteSectorsShort";
+
+const int MetricsDaemon::kMetricStatsShortInterval = 1;  // seconds
+const int MetricsDaemon::kMetricStatsLongInterval = 30;  // seconds
+
+const int MetricsDaemon::kMetricMeminfoInterval = 30;        // seconds
+
+// Assume a max rate of 250Mb/s for reads (worse for writes) and 512 byte
+// sectors.
+const int MetricsDaemon::kMetricSectorsIOMax = 500000;  // sectors/second
+const int MetricsDaemon::kMetricSectorsBuckets = 50;    // buckets
+// Page size is 4k, sector size is 0.5k.  We're not interested in page fault
+// rates that the disk cannot sustain.
+const int MetricsDaemon::kMetricPageFaultsMax = kMetricSectorsIOMax / 8;
+const int MetricsDaemon::kMetricPageFaultsBuckets = 50;
+
+// Major page faults, i.e. the ones that require data to be read from disk.
+
+const char MetricsDaemon::kMetricPageFaultsLongName[] =
+    "Platform.PageFaultsLong";
+const char MetricsDaemon::kMetricPageFaultsShortName[] =
+    "Platform.PageFaultsShort";
+
+// Swap in and Swap out
+
+const char MetricsDaemon::kMetricSwapInLongName[] =
+    "Platform.SwapInLong";
+const char MetricsDaemon::kMetricSwapInShortName[] =
+    "Platform.SwapInShort";
+
+const char MetricsDaemon::kMetricSwapOutLongName[] =
+    "Platform.SwapOutLong";
+const char MetricsDaemon::kMetricSwapOutShortName[] =
+    "Platform.SwapOutShort";
+
+const char MetricsDaemon::kMetricsProcStatFileName[] = "/proc/stat";
+const int MetricsDaemon::kMetricsProcStatFirstLineItemsCount = 11;
+
+// Thermal CPU throttling.
+
+const char MetricsDaemon::kMetricScaledCpuFrequencyName[] =
+    "Platform.CpuFrequencyThermalScaling";
+
+// Zram sysfs entries.
+
+const char MetricsDaemon::kComprDataSizeName[] = "compr_data_size";
+const char MetricsDaemon::kOrigDataSizeName[] = "orig_data_size";
+const char MetricsDaemon::kZeroPagesName[] = "zero_pages";
+
+// Memory use stats collection intervals.  We collect some memory use interval
+// at these intervals after boot, and we stop collecting after the last one,
+// with the assumption that in most cases the memory use won't change much
+// after that.
+static const int kMemuseIntervals[] = {
+  1 * kSecondsPerMinute,    // 1 minute mark
+  4 * kSecondsPerMinute,    // 5 minute mark
+  25 * kSecondsPerMinute,   // 0.5 hour mark
+  120 * kSecondsPerMinute,  // 2.5 hour mark
+  600 * kSecondsPerMinute,  // 12.5 hour mark
+};
+
+MetricsDaemon::MetricsDaemon()
+    : memuse_final_time_(0),
+      memuse_interval_index_(0),
+      read_sectors_(0),
+      write_sectors_(0),
+      vmstats_(),
+      stats_state_(kStatsShort),
+      stats_initial_time_(0),
+      ticks_per_second_(0),
+      latest_cpu_use_ticks_(0) {}
+
+MetricsDaemon::~MetricsDaemon() {
+}
+
+double MetricsDaemon::GetActiveTime() {
+  struct timespec ts;
+  int r = clock_gettime(CLOCK_MONOTONIC, &ts);
+  if (r < 0) {
+    PLOG(WARNING) << "clock_gettime(CLOCK_MONOTONIC) failed";
+    return 0;
+  } else {
+    return ts.tv_sec + static_cast<double>(ts.tv_nsec) / (1000 * 1000 * 1000);
+  }
+}
+
+int MetricsDaemon::Run() {
+  if (CheckSystemCrash(kKernelCrashDetectedFile)) {
+    ProcessKernelCrash();
+  }
+
+  if (CheckSystemCrash(kUncleanShutdownDetectedFile)) {
+    ProcessUncleanShutdown();
+  }
+
+  // On OS version change, clear version stats (which are reported daily).
+  int32_t version = GetOsVersionHash();
+  if (version_cycle_->Get() != version) {
+    version_cycle_->Set(version);
+    kernel_crashes_version_count_->Set(0);
+    version_cumulative_active_use_->Set(0);
+    version_cumulative_cpu_use_->Set(0);
+  }
+
+  return chromeos::DBusDaemon::Run();
+}
+
+void MetricsDaemon::RunUploaderTest() {
+  upload_service_.reset(new UploadService(new SystemProfileCache(true,
+                                                                 config_root_),
+                                          metrics_lib_,
+                                          server_));
+  upload_service_->Init(upload_interval_, metrics_file_);
+  upload_service_->UploadEvent();
+}
+
+uint32_t MetricsDaemon::GetOsVersionHash() {
+  static uint32_t cached_version_hash = 0;
+  static bool version_hash_is_cached = false;
+  if (version_hash_is_cached)
+    return cached_version_hash;
+  version_hash_is_cached = true;
+  std::string version = metrics::kDefaultVersion;
+  // The version might not be set for development devices. In this case, use the
+  // zero version.
+  base::SysInfo::GetLsbReleaseValue("BRILLO_VERSION", &version);
+  cached_version_hash = base::Hash(version);
+  if (testing_) {
+    cached_version_hash = 42;  // return any plausible value for the hash
+  }
+  return cached_version_hash;
+}
+
+void MetricsDaemon::Init(bool testing,
+                         bool uploader_active,
+                         bool dbus_enabled,
+                         MetricsLibraryInterface* metrics_lib,
+                         const string& vmstats_path,
+                         const string& scaling_max_freq_path,
+                         const string& cpuinfo_max_freq_path,
+                         const base::TimeDelta& upload_interval,
+                         const string& server,
+                         const string& metrics_file,
+                         const string& config_root) {
+  testing_ = testing;
+  uploader_active_ = uploader_active;
+  dbus_enabled_ = dbus_enabled;
+  config_root_ = config_root;
+  DCHECK(metrics_lib != nullptr);
+  metrics_lib_ = metrics_lib;
+
+  upload_interval_ = upload_interval;
+  server_ = server;
+  metrics_file_ = metrics_file;
+
+  // Get ticks per second (HZ) on this system.
+  // Sysconf cannot fail, so no sanity checks are needed.
+  ticks_per_second_ = sysconf(_SC_CLK_TCK);
+
+  daily_active_use_.reset(
+      new PersistentInteger("Platform.DailyUseTime"));
+  version_cumulative_active_use_.reset(
+      new PersistentInteger("Platform.CumulativeDailyUseTime"));
+  version_cumulative_cpu_use_.reset(
+      new PersistentInteger("Platform.CumulativeCpuTime"));
+
+  kernel_crash_interval_.reset(
+      new PersistentInteger("Platform.KernelCrashInterval"));
+  unclean_shutdown_interval_.reset(
+      new PersistentInteger("Platform.UncleanShutdownInterval"));
+  user_crash_interval_.reset(
+      new PersistentInteger("Platform.UserCrashInterval"));
+
+  any_crashes_daily_count_.reset(
+      new PersistentInteger("Platform.AnyCrashesDaily"));
+  any_crashes_weekly_count_.reset(
+      new PersistentInteger("Platform.AnyCrashesWeekly"));
+  user_crashes_daily_count_.reset(
+      new PersistentInteger("Platform.UserCrashesDaily"));
+  user_crashes_weekly_count_.reset(
+      new PersistentInteger("Platform.UserCrashesWeekly"));
+  kernel_crashes_daily_count_.reset(
+      new PersistentInteger("Platform.KernelCrashesDaily"));
+  kernel_crashes_weekly_count_.reset(
+      new PersistentInteger("Platform.KernelCrashesWeekly"));
+  kernel_crashes_version_count_.reset(
+      new PersistentInteger("Platform.KernelCrashesSinceUpdate"));
+  unclean_shutdowns_daily_count_.reset(
+      new PersistentInteger("Platform.UncleanShutdownsDaily"));
+  unclean_shutdowns_weekly_count_.reset(
+      new PersistentInteger("Platform.UncleanShutdownsWeekly"));
+
+  daily_cycle_.reset(new PersistentInteger("daily.cycle"));
+  weekly_cycle_.reset(new PersistentInteger("weekly.cycle"));
+  version_cycle_.reset(new PersistentInteger("version.cycle"));
+
+  vmstats_path_ = vmstats_path;
+  scaling_max_freq_path_ = scaling_max_freq_path;
+  cpuinfo_max_freq_path_ = cpuinfo_max_freq_path;
+}
+
+int MetricsDaemon::OnInit() {
+  int return_code = dbus_enabled_ ? chromeos::DBusDaemon::OnInit() :
+      chromeos::Daemon::OnInit();
+  if (return_code != EX_OK)
+    return return_code;
+
+  if (testing_)
+    return EX_OK;
+
+  if (dbus_enabled_) {
+    bus_->AssertOnDBusThread();
+    CHECK(bus_->SetUpAsyncOperations());
+
+    if (bus_->is_connected()) {
+      const std::string match_rule =
+          base::StringPrintf(kCrashReporterMatchRule,
+                             kCrashReporterInterface,
+                             kCrashReporterUserCrashSignal);
+
+      bus_->AddFilterFunction(&MetricsDaemon::MessageFilter, this);
+
+      DBusError error;
+      dbus_error_init(&error);
+      bus_->AddMatch(match_rule, &error);
+
+      if (dbus_error_is_set(&error)) {
+        LOG(ERROR) << "Failed to add match rule \"" << match_rule << "\". Got "
+            << error.name << ": " << error.message;
+        return EX_SOFTWARE;
+      }
+    } else {
+      LOG(ERROR) << "DBus isn't connected.";
+      return EX_UNAVAILABLE;
+    }
+  }
+
+  if (uploader_active_) {
+    upload_service_.reset(
+        new UploadService(new SystemProfileCache(), metrics_lib_, server_));
+    upload_service_->Init(upload_interval_, metrics_file_);
+  }
+
+  return EX_OK;
+}
+
+void MetricsDaemon::OnShutdown(int* return_code) {
+  if (!testing_ && dbus_enabled_ && bus_->is_connected()) {
+    const std::string match_rule =
+        base::StringPrintf(kCrashReporterMatchRule,
+                           kCrashReporterInterface,
+                           kCrashReporterUserCrashSignal);
+
+    bus_->RemoveFilterFunction(&MetricsDaemon::MessageFilter, this);
+
+    DBusError error;
+    dbus_error_init(&error);
+    bus_->RemoveMatch(match_rule, &error);
+
+    if (dbus_error_is_set(&error)) {
+      LOG(ERROR) << "Failed to remove match rule \"" << match_rule << "\". Got "
+          << error.name << ": " << error.message;
+    }
+  }
+  chromeos::DBusDaemon::OnShutdown(return_code);
+}
+
+// static
+DBusHandlerResult MetricsDaemon::MessageFilter(DBusConnection* connection,
+                                               DBusMessage* message,
+                                               void* user_data) {
+  int message_type = dbus_message_get_type(message);
+  if (message_type != DBUS_MESSAGE_TYPE_SIGNAL) {
+    DLOG(WARNING) << "unexpected message type " << message_type;
+    return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+  }
+
+  // Signal messages always have interfaces.
+  const std::string interface(dbus_message_get_interface(message));
+  const std::string member(dbus_message_get_member(message));
+  DLOG(INFO) << "Got " << interface << "." << member << " D-Bus signal";
+
+  MetricsDaemon* daemon = static_cast<MetricsDaemon*>(user_data);
+
+  DBusMessageIter iter;
+  dbus_message_iter_init(message, &iter);
+  if (interface == kCrashReporterInterface) {
+    CHECK_EQ(member, kCrashReporterUserCrashSignal);
+    daemon->ProcessUserCrash();
+  } else {
+    // Ignore messages from the bus itself.
+    return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+  }
+
+  return DBUS_HANDLER_RESULT_HANDLED;
+}
+
+// One might argue that parts of this should go into
+// chromium/src/base/sys_info_chromeos.c instead, but put it here for now.
+
+TimeDelta MetricsDaemon::GetIncrementalCpuUse() {
+  FilePath proc_stat_path = FilePath(kMetricsProcStatFileName);
+  std::string proc_stat_string;
+  if (!base::ReadFileToString(proc_stat_path, &proc_stat_string)) {
+    LOG(WARNING) << "cannot open " << kMetricsProcStatFileName;
+    return TimeDelta();
+  }
+
+  std::vector<std::string> proc_stat_lines;
+  base::SplitString(proc_stat_string, '\n', &proc_stat_lines);
+  if (proc_stat_lines.empty()) {
+    LOG(WARNING) << "cannot parse " << kMetricsProcStatFileName
+                 << ": " << proc_stat_string;
+    return TimeDelta();
+  }
+  std::vector<std::string> proc_stat_totals;
+  base::SplitStringAlongWhitespace(proc_stat_lines[0], &proc_stat_totals);
+
+  uint64_t user_ticks, user_nice_ticks, system_ticks;
+  if (proc_stat_totals.size() != kMetricsProcStatFirstLineItemsCount ||
+      proc_stat_totals[0] != "cpu" ||
+      !base::StringToUint64(proc_stat_totals[1], &user_ticks) ||
+      !base::StringToUint64(proc_stat_totals[2], &user_nice_ticks) ||
+      !base::StringToUint64(proc_stat_totals[3], &system_ticks)) {
+    LOG(WARNING) << "cannot parse first line: " << proc_stat_lines[0];
+    return TimeDelta(base::TimeDelta::FromSeconds(0));
+  }
+
+  uint64_t total_cpu_use_ticks = user_ticks + user_nice_ticks + system_ticks;
+
+  // Sanity check.
+  if (total_cpu_use_ticks < latest_cpu_use_ticks_) {
+    LOG(WARNING) << "CPU time decreasing from " << latest_cpu_use_ticks_
+                 << " to " << total_cpu_use_ticks;
+    return TimeDelta();
+  }
+
+  uint64_t diff = total_cpu_use_ticks - latest_cpu_use_ticks_;
+  latest_cpu_use_ticks_ = total_cpu_use_ticks;
+  // Use microseconds to avoid significant truncations.
+  return base::TimeDelta::FromMicroseconds(
+      diff * 1000 * 1000 / ticks_per_second_);
+}
+
+void MetricsDaemon::ProcessUserCrash() {
+  // Counts the active time up to now.
+  UpdateStats(TimeTicks::Now(), Time::Now());
+
+  // Reports the active use time since the last crash and resets it.
+  SendCrashIntervalSample(user_crash_interval_);
+
+  any_crashes_daily_count_->Add(1);
+  any_crashes_weekly_count_->Add(1);
+  user_crashes_daily_count_->Add(1);
+  user_crashes_weekly_count_->Add(1);
+}
+
+void MetricsDaemon::ProcessKernelCrash() {
+  // Counts the active time up to now.
+  UpdateStats(TimeTicks::Now(), Time::Now());
+
+  // Reports the active use time since the last crash and resets it.
+  SendCrashIntervalSample(kernel_crash_interval_);
+
+  any_crashes_daily_count_->Add(1);
+  any_crashes_weekly_count_->Add(1);
+  kernel_crashes_daily_count_->Add(1);
+  kernel_crashes_weekly_count_->Add(1);
+
+  kernel_crashes_version_count_->Add(1);
+}
+
+void MetricsDaemon::ProcessUncleanShutdown() {
+  // Counts the active time up to now.
+  UpdateStats(TimeTicks::Now(), Time::Now());
+
+  // Reports the active use time since the last crash and resets it.
+  SendCrashIntervalSample(unclean_shutdown_interval_);
+
+  unclean_shutdowns_daily_count_->Add(1);
+  unclean_shutdowns_weekly_count_->Add(1);
+  any_crashes_daily_count_->Add(1);
+  any_crashes_weekly_count_->Add(1);
+}
+
+bool MetricsDaemon::CheckSystemCrash(const string& crash_file) {
+  FilePath crash_detected(crash_file);
+  if (!base::PathExists(crash_detected))
+    return false;
+
+  // Deletes the crash-detected file so that the daemon doesn't report
+  // another kernel crash in case it's restarted.
+  base::DeleteFile(crash_detected, false);  // not recursive
+  return true;
+}
+
+void MetricsDaemon::StatsReporterInit() {
+  DiskStatsReadStats(&read_sectors_, &write_sectors_);
+  VmStatsReadStats(&vmstats_);
+  // The first time around just run the long stat, so we don't delay boot.
+  stats_state_ = kStatsLong;
+  stats_initial_time_ = GetActiveTime();
+  if (stats_initial_time_ < 0) {
+    LOG(WARNING) << "not collecting disk stats";
+  } else {
+    ScheduleStatsCallback(kMetricStatsLongInterval);
+  }
+}
+
+void MetricsDaemon::ScheduleStatsCallback(int wait) {
+  if (testing_) {
+    return;
+  }
+  base::MessageLoop::current()->PostDelayedTask(FROM_HERE,
+      base::Bind(&MetricsDaemon::StatsCallback, base::Unretained(this)),
+      base::TimeDelta::FromSeconds(wait));
+}
+
+bool MetricsDaemon::VmStatsParseStats(const char* stats,
+                                      struct VmstatRecord* record) {
+  // a mapping of string name to field in VmstatRecord and whether we found it
+  struct mapping {
+    const string name;
+    uint64_t* value_p;
+    bool found;
+  } map[] =
+      { { .name = "pgmajfault",
+          .value_p = &record->page_faults_,
+          .found = false },
+        { .name = "pswpin",
+          .value_p = &record->swap_in_,
+          .found = false },
+        { .name = "pswpout",
+          .value_p = &record->swap_out_,
+          .found = false }, };
+
+  // Each line in the file has the form
+  // <ID> <VALUE>
+  // for instance:
+  // nr_free_pages 213427
+  vector<string> lines;
+  Tokenize(stats, "\n", &lines);
+  for (vector<string>::iterator it = lines.begin();
+       it != lines.end(); ++it) {
+    vector<string> tokens;
+    base::SplitString(*it, ' ', &tokens);
+    if (tokens.size() == 2) {
+      for (unsigned int i = 0; i < sizeof(map)/sizeof(struct mapping); i++) {
+        if (!tokens[0].compare(map[i].name)) {
+          if (!base::StringToUint64(tokens[1], map[i].value_p))
+            return false;
+          map[i].found = true;
+        }
+      }
+    } else {
+      LOG(WARNING) << "unexpected vmstat format";
+    }
+  }
+  // make sure we got all the stats
+  for (unsigned i = 0; i < sizeof(map)/sizeof(struct mapping); i++) {
+    if (map[i].found == false) {
+      LOG(WARNING) << "vmstat missing " << map[i].name;
+      return false;
+    }
+  }
+  return true;
+}
+
+bool MetricsDaemon::VmStatsReadStats(struct VmstatRecord* stats) {
+  string value_string;
+  FilePath* path = new FilePath(vmstats_path_);
+  if (!base::ReadFileToString(*path, &value_string)) {
+    delete path;
+    LOG(WARNING) << "cannot read " << vmstats_path_;
+    return false;
+  }
+  delete path;
+  return VmStatsParseStats(value_string.c_str(), stats);
+}
+
+bool MetricsDaemon::ReadFreqToInt(const string& sysfs_file_name, int* value) {
+  const FilePath sysfs_path(sysfs_file_name);
+  string value_string;
+  if (!base::ReadFileToString(sysfs_path, &value_string)) {
+    LOG(WARNING) << "cannot read " << sysfs_path.value().c_str();
+    return false;
+  }
+  if (!base::RemoveChars(value_string, "\n", &value_string)) {
+    LOG(WARNING) << "no newline in " << value_string;
+    // Continue even though the lack of newline is suspicious.
+  }
+  if (!base::StringToInt(value_string, value)) {
+    LOG(WARNING) << "cannot convert " << value_string << " to int";
+    return false;
+  }
+  return true;
+}
+
+void MetricsDaemon::SendCpuThrottleMetrics() {
+  // |max_freq| is 0 only the first time through.
+  static int max_freq = 0;
+  if (max_freq == -1)
+    // Give up, as sysfs did not report max_freq correctly.
+    return;
+  if (max_freq == 0 || testing_) {
+    // One-time initialization of max_freq.  (Every time when testing.)
+    if (!ReadFreqToInt(cpuinfo_max_freq_path_, &max_freq)) {
+      max_freq = -1;
+      return;
+    }
+    if (max_freq == 0) {
+      LOG(WARNING) << "sysfs reports 0 max CPU frequency\n";
+      max_freq = -1;
+      return;
+    }
+    if (max_freq % 10000 == 1000) {
+      // Special case: system has turbo mode, and max non-turbo frequency is
+      // max_freq - 1000.  This relies on "normal" (non-turbo) frequencies
+      // being multiples of (at least) 10 MHz.  Although there is no guarantee
+      // of this, it seems a fairly reasonable assumption.  Otherwise we should
+      // read scaling_available_frequencies, sort the frequencies, compare the
+      // two highest ones, and check if they differ by 1000 (kHz) (and that's a
+      // hack too, no telling when it will change).
+      max_freq -= 1000;
+    }
+  }
+  int scaled_freq = 0;
+  if (!ReadFreqToInt(scaling_max_freq_path_, &scaled_freq))
+    return;
+  // Frequencies are in kHz.  If scaled_freq > max_freq, turbo is on, but
+  // scaled_freq is not the actual turbo frequency.  We indicate this situation
+  // with a 101% value.
+  int percent = scaled_freq > max_freq ? 101 : scaled_freq / (max_freq / 100);
+  SendLinearSample(kMetricScaledCpuFrequencyName, percent, 101, 102);
+}
+
+// Collects disk and vm stats alternating over a short and a long interval.
+
+void MetricsDaemon::StatsCallback() {
+  uint64_t read_sectors_now, write_sectors_now;
+  struct VmstatRecord vmstats_now;
+  double time_now = GetActiveTime();
+  double delta_time = time_now - stats_initial_time_;
+  if (testing_) {
+    // Fake the time when testing.
+    delta_time = stats_state_ == kStatsShort ?
+        kMetricStatsShortInterval : kMetricStatsLongInterval;
+  }
+  bool diskstats_success = DiskStatsReadStats(&read_sectors_now,
+                                              &write_sectors_now);
+  int delta_read = read_sectors_now - read_sectors_;
+  int delta_write = write_sectors_now - write_sectors_;
+  int read_sectors_per_second = delta_read / delta_time;
+  int write_sectors_per_second = delta_write / delta_time;
+  bool vmstats_success = VmStatsReadStats(&vmstats_now);
+  uint64_t delta_faults = vmstats_now.page_faults_ - vmstats_.page_faults_;
+  uint64_t delta_swap_in = vmstats_now.swap_in_ - vmstats_.swap_in_;
+  uint64_t delta_swap_out = vmstats_now.swap_out_ - vmstats_.swap_out_;
+  uint64_t page_faults_per_second = delta_faults / delta_time;
+  uint64_t swap_in_per_second = delta_swap_in / delta_time;
+  uint64_t swap_out_per_second = delta_swap_out / delta_time;
+
+  switch (stats_state_) {
+    case kStatsShort:
+      if (diskstats_success) {
+        SendSample(kMetricReadSectorsShortName,
+                   read_sectors_per_second,
+                   1,
+                   kMetricSectorsIOMax,
+                   kMetricSectorsBuckets);
+        SendSample(kMetricWriteSectorsShortName,
+                   write_sectors_per_second,
+                   1,
+                   kMetricSectorsIOMax,
+                   kMetricSectorsBuckets);
+      }
+      if (vmstats_success) {
+        SendSample(kMetricPageFaultsShortName,
+                   page_faults_per_second,
+                   1,
+                   kMetricPageFaultsMax,
+                   kMetricPageFaultsBuckets);
+        SendSample(kMetricSwapInShortName,
+                   swap_in_per_second,
+                   1,
+                   kMetricPageFaultsMax,
+                   kMetricPageFaultsBuckets);
+        SendSample(kMetricSwapOutShortName,
+                   swap_out_per_second,
+                   1,
+                   kMetricPageFaultsMax,
+                   kMetricPageFaultsBuckets);
+      }
+      // Schedule long callback.
+      stats_state_ = kStatsLong;
+      ScheduleStatsCallback(kMetricStatsLongInterval -
+                            kMetricStatsShortInterval);
+      break;
+    case kStatsLong:
+      if (diskstats_success) {
+        SendSample(kMetricReadSectorsLongName,
+                   read_sectors_per_second,
+                   1,
+                   kMetricSectorsIOMax,
+                   kMetricSectorsBuckets);
+        SendSample(kMetricWriteSectorsLongName,
+                   write_sectors_per_second,
+                   1,
+                   kMetricSectorsIOMax,
+                   kMetricSectorsBuckets);
+        // Reset sector counters.
+        read_sectors_ = read_sectors_now;
+        write_sectors_ = write_sectors_now;
+      }
+      if (vmstats_success) {
+        SendSample(kMetricPageFaultsLongName,
+                   page_faults_per_second,
+                   1,
+                   kMetricPageFaultsMax,
+                   kMetricPageFaultsBuckets);
+        SendSample(kMetricSwapInLongName,
+                   swap_in_per_second,
+                   1,
+                   kMetricPageFaultsMax,
+                   kMetricPageFaultsBuckets);
+        SendSample(kMetricSwapOutLongName,
+                   swap_out_per_second,
+                   1,
+                   kMetricPageFaultsMax,
+                   kMetricPageFaultsBuckets);
+
+        vmstats_ = vmstats_now;
+      }
+      SendCpuThrottleMetrics();
+      // Set start time for new cycle.
+      stats_initial_time_ = time_now;
+      // Schedule short callback.
+      stats_state_ = kStatsShort;
+      ScheduleStatsCallback(kMetricStatsShortInterval);
+      break;
+    default:
+      LOG(FATAL) << "Invalid stats state";
+  }
+}
+
+void MetricsDaemon::ScheduleMeminfoCallback(int wait) {
+  if (testing_) {
+    return;
+  }
+  base::TimeDelta waitDelta = base::TimeDelta::FromSeconds(wait);
+  base::MessageLoop::current()->PostDelayedTask(FROM_HERE,
+      base::Bind(&MetricsDaemon::MeminfoCallback, base::Unretained(this),
+                 waitDelta),
+      waitDelta);
+}
+
+void MetricsDaemon::MeminfoCallback(base::TimeDelta wait) {
+  string meminfo_raw;
+  const FilePath meminfo_path("/proc/meminfo");
+  if (!base::ReadFileToString(meminfo_path, &meminfo_raw)) {
+    LOG(WARNING) << "cannot read " << meminfo_path.value().c_str();
+    return;
+  }
+  // Make both calls even if the first one fails.
+  bool success = ProcessMeminfo(meminfo_raw);
+  bool reschedule =
+      ReportZram(base::FilePath(FILE_PATH_LITERAL("/sys/block/zram0"))) &&
+      success;
+  if (reschedule) {
+    base::MessageLoop::current()->PostDelayedTask(FROM_HERE,
+        base::Bind(&MetricsDaemon::MeminfoCallback, base::Unretained(this),
+                   wait),
+        wait);
+  }
+}
+
+// static
+bool MetricsDaemon::ReadFileToUint64(const base::FilePath& path,
+                                     uint64_t* value) {
+  std::string content;
+  if (!base::ReadFileToString(path, &content)) {
+    PLOG(WARNING) << "cannot read " << path.MaybeAsASCII();
+    return false;
+  }
+  // Remove final newline.
+  base::TrimWhitespaceASCII(content, base::TRIM_TRAILING, &content);
+  if (!base::StringToUint64(content, value)) {
+    LOG(WARNING) << "invalid integer: " << content;
+    return false;
+  }
+  return true;
+}
+
+bool MetricsDaemon::ReportZram(const base::FilePath& zram_dir) {
+  // Data sizes are in bytes.  |zero_pages| is in number of pages.
+  uint64_t compr_data_size, orig_data_size, zero_pages;
+  const size_t page_size = 4096;
+
+  if (!ReadFileToUint64(zram_dir.Append(kComprDataSizeName),
+                        &compr_data_size) ||
+      !ReadFileToUint64(zram_dir.Append(kOrigDataSizeName), &orig_data_size) ||
+      !ReadFileToUint64(zram_dir.Append(kZeroPagesName), &zero_pages)) {
+    return false;
+  }
+
+  // |orig_data_size| does not include zero-filled pages.
+  orig_data_size += zero_pages * page_size;
+
+  const int compr_data_size_mb = compr_data_size >> 20;
+  const int savings_mb = (orig_data_size - compr_data_size) >> 20;
+  const int zero_ratio_percent = zero_pages * page_size * 100 / orig_data_size;
+
+  // Report compressed size in megabytes.  100 MB or less has little impact.
+  SendSample("Platform.ZramCompressedSize", compr_data_size_mb, 100, 4000, 50);
+  SendSample("Platform.ZramSavings", savings_mb, 100, 4000, 50);
+  // The compression ratio is multiplied by 100 for better resolution.  The
+  // ratios of interest are between 1 and 6 (100% and 600% as reported).  We
+  // don't want samples when very little memory is being compressed.
+  if (compr_data_size_mb >= 1) {
+    SendSample("Platform.ZramCompressionRatioPercent",
+               orig_data_size * 100 / compr_data_size, 100, 600, 50);
+  }
+  // The values of interest for zero_pages are between 1MB and 1GB.  The units
+  // are number of pages.
+  SendSample("Platform.ZramZeroPages", zero_pages, 256, 256 * 1024, 50);
+  SendSample("Platform.ZramZeroRatioPercent", zero_ratio_percent, 1, 50, 50);
+
+  return true;
+}
+
+bool MetricsDaemon::ProcessMeminfo(const string& meminfo_raw) {
+  static const MeminfoRecord fields_array[] = {
+    { "MemTotal", "MemTotal" },  // SPECIAL CASE: total system memory
+    { "MemFree", "MemFree" },
+    { "Buffers", "Buffers" },
+    { "Cached", "Cached" },
+    // { "SwapCached", "SwapCached" },
+    { "Active", "Active" },
+    { "Inactive", "Inactive" },
+    { "ActiveAnon", "Active(anon)" },
+    { "InactiveAnon", "Inactive(anon)" },
+    { "ActiveFile" , "Active(file)" },
+    { "InactiveFile", "Inactive(file)" },
+    { "Unevictable", "Unevictable", kMeminfoOp_HistLog },
+    // { "Mlocked", "Mlocked" },
+    { "SwapTotal", "SwapTotal", kMeminfoOp_SwapTotal },
+    { "SwapFree", "SwapFree", kMeminfoOp_SwapFree },
+    // { "Dirty", "Dirty" },
+    // { "Writeback", "Writeback" },
+    { "AnonPages", "AnonPages" },
+    { "Mapped", "Mapped" },
+    { "Shmem", "Shmem", kMeminfoOp_HistLog },
+    { "Slab", "Slab", kMeminfoOp_HistLog },
+    // { "SReclaimable", "SReclaimable" },
+    // { "SUnreclaim", "SUnreclaim" },
+  };
+  vector<MeminfoRecord> fields(fields_array,
+                               fields_array + arraysize(fields_array));
+  if (!FillMeminfo(meminfo_raw, &fields)) {
+    return false;
+  }
+  int total_memory = fields[0].value;
+  if (total_memory == 0) {
+    // this "cannot happen"
+    LOG(WARNING) << "borked meminfo parser";
+    return false;
+  }
+  int swap_total = 0;
+  int swap_free = 0;
+  // Send all fields retrieved, except total memory.
+  for (unsigned int i = 1; i < fields.size(); i++) {
+    string metrics_name = base::StringPrintf("Platform.Meminfo%s",
+                                             fields[i].name);
+    int percent;
+    switch (fields[i].op) {
+      case kMeminfoOp_HistPercent:
+        // report value as percent of total memory
+        percent = fields[i].value * 100 / total_memory;
+        SendLinearSample(metrics_name, percent, 100, 101);
+        break;
+      case kMeminfoOp_HistLog:
+        // report value in kbytes, log scale, 4Gb max
+        SendSample(metrics_name, fields[i].value, 1, 4 * 1000 * 1000, 100);
+        break;
+      case kMeminfoOp_SwapTotal:
+        swap_total = fields[i].value;
+      case kMeminfoOp_SwapFree:
+        swap_free = fields[i].value;
+        break;
+    }
+  }
+  if (swap_total > 0) {
+    int swap_used = swap_total - swap_free;
+    int swap_used_percent = swap_used * 100 / swap_total;
+    SendSample("Platform.MeminfoSwapUsed", swap_used, 1, 8 * 1000 * 1000, 100);
+    SendLinearSample("Platform.MeminfoSwapUsedPercent", swap_used_percent,
+                     100, 101);
+  }
+  return true;
+}
+
+bool MetricsDaemon::FillMeminfo(const string& meminfo_raw,
+                                vector<MeminfoRecord>* fields) {
+  vector<string> lines;
+  unsigned int nlines = Tokenize(meminfo_raw, "\n", &lines);
+
+  // Scan meminfo output and collect field values.  Each field name has to
+  // match a meminfo entry (case insensitive) after removing non-alpha
+  // characters from the entry.
+  unsigned int ifield = 0;
+  for (unsigned int iline = 0;
+       iline < nlines && ifield < fields->size();
+       iline++) {
+    vector<string> tokens;
+    Tokenize(lines[iline], ": ", &tokens);
+    if (strcmp((*fields)[ifield].match, tokens[0].c_str()) == 0) {
+      // Name matches. Parse value and save.
+      char* rest;
+      (*fields)[ifield].value =
+          static_cast<int>(strtol(tokens[1].c_str(), &rest, 10));
+      if (*rest != '\0') {
+        LOG(WARNING) << "missing meminfo value";
+        return false;
+      }
+      ifield++;
+    }
+  }
+  if (ifield < fields->size()) {
+    // End of input reached while scanning.
+    LOG(WARNING) << "cannot find field " << (*fields)[ifield].match
+                 << " and following";
+    return false;
+  }
+  return true;
+}
+
+void MetricsDaemon::ScheduleMemuseCallback(double interval) {
+  if (testing_) {
+    return;
+  }
+  base::MessageLoop::current()->PostDelayedTask(FROM_HERE,
+      base::Bind(&MetricsDaemon::MemuseCallback, base::Unretained(this)),
+      base::TimeDelta::FromSeconds(interval));
+}
+
+void MetricsDaemon::MemuseCallback() {
+  // Since we only care about active time (i.e. uptime minus sleep time) but
+  // the callbacks are driven by real time (uptime), we check if we should
+  // reschedule this callback due to intervening sleep periods.
+  double now = GetActiveTime();
+  // Avoid intervals of less than one second.
+  double remaining_time = ceil(memuse_final_time_ - now);
+  if (remaining_time > 0) {
+    ScheduleMemuseCallback(remaining_time);
+  } else {
+    // Report stats and advance the measurement interval unless there are
+    // errors or we've completed the last interval.
+    if (MemuseCallbackWork() &&
+        memuse_interval_index_ < arraysize(kMemuseIntervals)) {
+      double interval = kMemuseIntervals[memuse_interval_index_++];
+      memuse_final_time_ = now + interval;
+      ScheduleMemuseCallback(interval);
+    }
+  }
+}
+
+bool MetricsDaemon::MemuseCallbackWork() {
+  string meminfo_raw;
+  const FilePath meminfo_path("/proc/meminfo");
+  if (!base::ReadFileToString(meminfo_path, &meminfo_raw)) {
+    LOG(WARNING) << "cannot read " << meminfo_path.value().c_str();
+    return false;
+  }
+  return ProcessMemuse(meminfo_raw);
+}
+
+bool MetricsDaemon::ProcessMemuse(const string& meminfo_raw) {
+  static const MeminfoRecord fields_array[] = {
+    { "MemTotal", "MemTotal" },  // SPECIAL CASE: total system memory
+    { "ActiveAnon", "Active(anon)" },
+    { "InactiveAnon", "Inactive(anon)" },
+  };
+  vector<MeminfoRecord> fields(fields_array,
+                               fields_array + arraysize(fields_array));
+  if (!FillMeminfo(meminfo_raw, &fields)) {
+    return false;
+  }
+  int total = fields[0].value;
+  int active_anon = fields[1].value;
+  int inactive_anon = fields[2].value;
+  if (total == 0) {
+    // this "cannot happen"
+    LOG(WARNING) << "borked meminfo parser";
+    return false;
+  }
+  string metrics_name = base::StringPrintf("Platform.MemuseAnon%d",
+                                           memuse_interval_index_);
+  SendLinearSample(metrics_name, (active_anon + inactive_anon) * 100 / total,
+                   100, 101);
+  return true;
+}
+
+void MetricsDaemon::SendSample(const string& name, int sample,
+                               int min, int max, int nbuckets) {
+  metrics_lib_->SendToUMA(name, sample, min, max, nbuckets);
+}
+
+void MetricsDaemon::SendKernelCrashesCumulativeCountStats() {
+  // Report the number of crashes for this OS version, but don't clear the
+  // counter.  It is cleared elsewhere on version change.
+  int64_t crashes_count = kernel_crashes_version_count_->Get();
+  SendSample(kernel_crashes_version_count_->Name(),
+             crashes_count,
+             1,                         // value of first bucket
+             500,                       // value of last bucket
+             100);                      // number of buckets
+
+
+  int64_t cpu_use_ms = version_cumulative_cpu_use_->Get();
+  SendSample(version_cumulative_cpu_use_->Name(),
+             cpu_use_ms / 1000,         // stat is in seconds
+             1,                         // device may be used very little...
+             8 * 1000 * 1000,           // ... or a lot (a little over 90 days)
+             100);
+
+  // On the first run after an autoupdate, cpu_use_ms and active_use_seconds
+  // can be zero.  Avoid division by zero.
+  if (cpu_use_ms > 0) {
+    // Send the crash frequency since update in number of crashes per CPU year.
+    SendSample("Logging.KernelCrashesPerCpuYear",
+               crashes_count * kSecondsPerDay * 365 * 1000 / cpu_use_ms,
+               1,
+               1000 * 1000,     // about one crash every 30s of CPU time
+               100);
+  }
+
+  int64_t active_use_seconds = version_cumulative_active_use_->Get();
+  if (active_use_seconds > 0) {
+    SendSample(version_cumulative_active_use_->Name(),
+               active_use_seconds / 1000,  // stat is in seconds
+               1,                          // device may be used very little...
+               8 * 1000 * 1000,            // ... or a lot (about 90 days)
+               100);
+    // Same as above, but per year of active time.
+    SendSample("Logging.KernelCrashesPerActiveYear",
+               crashes_count * kSecondsPerDay * 365 / active_use_seconds,
+               1,
+               1000 * 1000,     // about one crash every 30s of active time
+               100);
+  }
+}
+
+void MetricsDaemon::SendDailyUseSample(
+    const scoped_ptr<PersistentInteger>& use) {
+  SendSample(use->Name(),
+             use->GetAndClear(),
+             1,                        // value of first bucket
+             kSecondsPerDay,           // value of last bucket
+             50);                      // number of buckets
+}
+
+void MetricsDaemon::SendCrashIntervalSample(
+    const scoped_ptr<PersistentInteger>& interval) {
+  SendSample(interval->Name(),
+             interval->GetAndClear(),
+             1,                        // value of first bucket
+             4 * kSecondsPerWeek,      // value of last bucket
+             50);                      // number of buckets
+}
+
+void MetricsDaemon::SendCrashFrequencySample(
+    const scoped_ptr<PersistentInteger>& frequency) {
+  SendSample(frequency->Name(),
+             frequency->GetAndClear(),
+             1,                        // value of first bucket
+             100,                      // value of last bucket
+             50);                      // number of buckets
+}
+
+void MetricsDaemon::SendLinearSample(const string& name, int sample,
+                                     int max, int nbuckets) {
+  // TODO(semenzato): add a proper linear histogram to the Chrome external
+  // metrics API.
+  LOG_IF(FATAL, nbuckets != max + 1) << "unsupported histogram scale";
+  metrics_lib_->SendEnumToUMA(name, sample, max);
+}
+
+void MetricsDaemon::UpdateStats(TimeTicks now_ticks,
+                                Time now_wall_time) {
+  const int elapsed_seconds = (now_ticks - last_update_stats_time_).InSeconds();
+  daily_active_use_->Add(elapsed_seconds);
+  version_cumulative_active_use_->Add(elapsed_seconds);
+  user_crash_interval_->Add(elapsed_seconds);
+  kernel_crash_interval_->Add(elapsed_seconds);
+  version_cumulative_cpu_use_->Add(GetIncrementalCpuUse().InMilliseconds());
+  last_update_stats_time_ = now_ticks;
+
+  const TimeDelta since_epoch = now_wall_time - Time::UnixEpoch();
+  const int day = since_epoch.InDays();
+  const int week = day / 7;
+
+  if (daily_cycle_->Get() != day) {
+    daily_cycle_->Set(day);
+    SendDailyUseSample(daily_active_use_);
+    SendDailyUseSample(version_cumulative_active_use_);
+    SendCrashFrequencySample(any_crashes_daily_count_);
+    SendCrashFrequencySample(user_crashes_daily_count_);
+    SendCrashFrequencySample(kernel_crashes_daily_count_);
+    SendCrashFrequencySample(unclean_shutdowns_daily_count_);
+    SendKernelCrashesCumulativeCountStats();
+  }
+
+  if (weekly_cycle_->Get() != week) {
+    weekly_cycle_->Set(week);
+    SendCrashFrequencySample(any_crashes_weekly_count_);
+    SendCrashFrequencySample(user_crashes_weekly_count_);
+    SendCrashFrequencySample(kernel_crashes_weekly_count_);
+    SendCrashFrequencySample(unclean_shutdowns_weekly_count_);
+  }
+}
+
+void MetricsDaemon::HandleUpdateStatsTimeout() {
+  UpdateStats(TimeTicks::Now(), Time::Now());
+  base::MessageLoop::current()->PostDelayedTask(FROM_HERE,
+      base::Bind(&MetricsDaemon::HandleUpdateStatsTimeout,
+                 base::Unretained(this)),
+      base::TimeDelta::FromMilliseconds(kUpdateStatsIntervalMs));
+}
diff --git a/metricsd/metrics_daemon.h b/metricsd/metrics_daemon.h
new file mode 100644
index 000000000..ccac52a19
--- /dev/null
+++ b/metricsd/metrics_daemon.h
@@ -0,0 +1,371 @@
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_METRICS_DAEMON_H_
+#define METRICS_METRICS_DAEMON_H_
+
+#include <stdint.h>
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include <base/files/file_path.h>
+#include <base/memory/scoped_ptr.h>
+#include <base/time/time.h>
+#include <chromeos/daemons/dbus_daemon.h>
+#include <gtest/gtest_prod.h>  // for FRIEND_TEST
+
+#include "metrics/metrics_library.h"
+#include "persistent_integer.h"
+#include "uploader/upload_service.h"
+
+using chromeos_metrics::PersistentInteger;
+
+class MetricsDaemon : public chromeos::DBusDaemon {
+ public:
+  MetricsDaemon();
+  ~MetricsDaemon();
+
+  // Initializes metrics class variables.
+  void Init(bool testing,
+            bool uploader_active,
+            bool dbus_enabled,
+            MetricsLibraryInterface* metrics_lib,
+            const std::string& vmstats_path,
+            const std::string& cpuinfo_max_freq_path,
+            const std::string& scaling_max_freq_path,
+            const base::TimeDelta& upload_interval,
+            const std::string& server,
+            const std::string& metrics_file,
+            const std::string& config_root);
+
+  // Initializes DBus and MessageLoop variables before running the MessageLoop.
+  int OnInit() override;
+
+  // Clean up data set up in OnInit before shutting down message loop.
+  void OnShutdown(int* return_code) override;
+
+  // Does all the work.
+  int Run() override;
+
+  // Triggers an upload event and exit. (Used to test UploadService)
+  void RunUploaderTest();
+
+ protected:
+  // Used also by the unit tests.
+  static const char kComprDataSizeName[];
+  static const char kOrigDataSizeName[];
+  static const char kZeroPagesName[];
+
+ private:
+  friend class MetricsDaemonTest;
+  FRIEND_TEST(MetricsDaemonTest, CheckSystemCrash);
+  FRIEND_TEST(MetricsDaemonTest, ComputeEpochNoCurrent);
+  FRIEND_TEST(MetricsDaemonTest, ComputeEpochNoLast);
+  FRIEND_TEST(MetricsDaemonTest, GetHistogramPath);
+  FRIEND_TEST(MetricsDaemonTest, IsNewEpoch);
+  FRIEND_TEST(MetricsDaemonTest, MessageFilter);
+  FRIEND_TEST(MetricsDaemonTest, ParseVmStats);
+  FRIEND_TEST(MetricsDaemonTest, ProcessKernelCrash);
+  FRIEND_TEST(MetricsDaemonTest, ProcessMeminfo);
+  FRIEND_TEST(MetricsDaemonTest, ProcessMeminfo2);
+  FRIEND_TEST(MetricsDaemonTest, ProcessUncleanShutdown);
+  FRIEND_TEST(MetricsDaemonTest, ProcessUserCrash);
+  FRIEND_TEST(MetricsDaemonTest, ReportCrashesDailyFrequency);
+  FRIEND_TEST(MetricsDaemonTest, ReadFreqToInt);
+  FRIEND_TEST(MetricsDaemonTest, ReportDiskStats);
+  FRIEND_TEST(MetricsDaemonTest, ReportKernelCrashInterval);
+  FRIEND_TEST(MetricsDaemonTest, ReportUncleanShutdownInterval);
+  FRIEND_TEST(MetricsDaemonTest, ReportUserCrashInterval);
+  FRIEND_TEST(MetricsDaemonTest, SendSample);
+  FRIEND_TEST(MetricsDaemonTest, SendCpuThrottleMetrics);
+  FRIEND_TEST(MetricsDaemonTest, SendZramMetrics);
+
+  // State for disk stats collector callback.
+  enum StatsState {
+    kStatsShort,    // short wait before short interval collection
+    kStatsLong,     // final wait before new collection
+  };
+
+  // Data record for aggregating daily usage.
+  class UseRecord {
+   public:
+    UseRecord() : day_(0), seconds_(0) {}
+    int day_;
+    int seconds_;
+  };
+
+  // Type of scale to use for meminfo histograms.  For most of them we use
+  // percent of total RAM, but for some we use absolute numbers, usually in
+  // megabytes, on a log scale from 0 to 4000, and 0 to 8000 for compressed
+  // swap (since it can be larger than total RAM).
+  enum MeminfoOp {
+    kMeminfoOp_HistPercent = 0,
+    kMeminfoOp_HistLog,
+    kMeminfoOp_SwapTotal,
+    kMeminfoOp_SwapFree,
+  };
+
+  // Record for retrieving and reporting values from /proc/meminfo.
+  struct MeminfoRecord {
+    const char* name;        // print name
+    const char* match;       // string to match in output of /proc/meminfo
+    MeminfoOp op;            // histogram scale selector, or other operator
+    int value;               // value from /proc/meminfo
+  };
+
+  // Record for retrieving and reporting values from /proc/vmstat
+  struct VmstatRecord {
+    uint64_t page_faults_;    // major faults
+    uint64_t swap_in_;        // pages swapped in
+    uint64_t swap_out_;       // pages swapped out
+  };
+
+  // Metric parameters.
+  static const char kMetricReadSectorsLongName[];
+  static const char kMetricReadSectorsShortName[];
+  static const char kMetricWriteSectorsLongName[];
+  static const char kMetricWriteSectorsShortName[];
+  static const char kMetricPageFaultsShortName[];
+  static const char kMetricPageFaultsLongName[];
+  static const char kMetricSwapInLongName[];
+  static const char kMetricSwapInShortName[];
+  static const char kMetricSwapOutLongName[];
+  static const char kMetricSwapOutShortName[];
+  static const char kMetricScaledCpuFrequencyName[];
+  static const int kMetricStatsShortInterval;
+  static const int kMetricStatsLongInterval;
+  static const int kMetricMeminfoInterval;
+  static const int kMetricSectorsIOMax;
+  static const int kMetricSectorsBuckets;
+  static const int kMetricPageFaultsMax;
+  static const int kMetricPageFaultsBuckets;
+  static const char kMetricsDiskStatsPath[];
+  static const char kMetricsVmStatsPath[];
+  static const char kMetricsProcStatFileName[];
+  static const int kMetricsProcStatFirstLineItemsCount;
+
+  // Returns the active time since boot (uptime minus sleep time) in seconds.
+  double GetActiveTime();
+
+  // D-Bus filter callback.
+  static DBusHandlerResult MessageFilter(DBusConnection* connection,
+                                         DBusMessage* message,
+                                         void* user_data);
+
+  // Updates the daily usage file, if necessary, by adding |seconds|
+  // of active use to the |day| since Epoch. If there's usage data for
+  // day in the past in the usage file, that data is sent to UMA and
+  // removed from the file. If there's already usage data for |day| in
+  // the usage file, the |seconds| are accumulated.
+  void LogDailyUseRecord(int day, int seconds);
+
+  // Updates the active use time and logs time between user-space
+  // process crashes.
+  void ProcessUserCrash();
+
+  // Updates the active use time and logs time between kernel crashes.
+  void ProcessKernelCrash();
+
+  // Updates the active use time and logs time between unclean shutdowns.
+  void ProcessUncleanShutdown();
+
+  // Checks if a kernel crash has been detected and returns true if
+  // so.  The method assumes that a kernel crash has happened if
+  // |crash_file| exists.  It removes the file immediately if it
+  // exists, so it must not be called more than once.
+  bool CheckSystemCrash(const std::string& crash_file);
+
+  // Sends a regular (exponential) histogram sample to Chrome for
+  // transport to UMA. See MetricsLibrary::SendToUMA in
+  // metrics_library.h for a description of the arguments.
+  void SendSample(const std::string& name, int sample,
+                  int min, int max, int nbuckets);
+
+  // Sends a linear histogram sample to Chrome for transport to UMA. See
+  // MetricsLibrary::SendToUMA in metrics_library.h for a description of the
+  // arguments.
+  void SendLinearSample(const std::string& name, int sample,
+                        int max, int nbuckets);
+
+  // Sends various cumulative kernel crash-related stats, for instance the
+  // total number of kernel crashes since the last version update.
+  void SendKernelCrashesCumulativeCountStats();
+
+  // Returns the total (system-wide) CPU usage between the time of the most
+  // recent call to this function and now.
+  base::TimeDelta GetIncrementalCpuUse();
+
+  // Sends a sample representing the number of seconds of active use
+  // for a 24-hour period.
+  void SendDailyUseSample(const scoped_ptr<PersistentInteger>& use);
+
+  // Sends a sample representing a time interval between two crashes of the
+  // same type.
+  void SendCrashIntervalSample(const scoped_ptr<PersistentInteger>& interval);
+
+  // Sends a sample representing a frequency of crashes of some type.
+  void SendCrashFrequencySample(const scoped_ptr<PersistentInteger>& frequency);
+
+  // Initializes vm and disk stats reporting.
+  void StatsReporterInit();
+
+  // Schedules a callback for the next vm and disk stats collection.
+  void ScheduleStatsCallback(int wait);
+
+  // Reads cumulative disk statistics from sysfs.  Returns true for success.
+  bool DiskStatsReadStats(uint64_t* read_sectors, uint64_t* write_sectors);
+
+  // Reads cumulative vm statistics from procfs.  Returns true for success.
+  bool VmStatsReadStats(struct VmstatRecord* stats);
+
+  // Parse cumulative vm statistics from a C string.  Returns true for success.
+  bool VmStatsParseStats(const char* stats, struct VmstatRecord* record);
+
+  // Reports disk and vm statistics.
+  void StatsCallback();
+
+  // Schedules meminfo collection callback.
+  void ScheduleMeminfoCallback(int wait);
+
+  // Reports memory statistics.  Reschedules callback on success.
+  void MeminfoCallback(base::TimeDelta wait);
+
+  // Parses content of /proc/meminfo and sends fields of interest to UMA.
+  // Returns false on errors.  |meminfo_raw| contains the content of
+  // /proc/meminfo.
+  bool ProcessMeminfo(const std::string& meminfo_raw);
+
+  // Parses meminfo data from |meminfo_raw|.  |fields| is a vector containing
+  // the fields of interest.  The order of the fields must be the same in which
+  // /proc/meminfo prints them.  The result of parsing fields[i] is placed in
+  // fields[i].value.
+  bool FillMeminfo(const std::string& meminfo_raw,
+                   std::vector<MeminfoRecord>* fields);
+
+  // Schedule a memory use callback in |interval| seconds.
+  void ScheduleMemuseCallback(double interval);
+
+  // Calls MemuseCallbackWork, and possibly schedules next callback, if enough
+  // active time has passed.  Otherwise reschedules itself to simulate active
+  // time callbacks (i.e. wall clock time minus sleep time).
+  void MemuseCallback();
+
+  // Reads /proc/meminfo and sends total anonymous memory usage to UMA.
+  bool MemuseCallbackWork();
+
+  // Parses meminfo data and sends it to UMA.
+  bool ProcessMemuse(const std::string& meminfo_raw);
+
+  // Sends stats for thermal CPU throttling.
+  void SendCpuThrottleMetrics();
+
+  // Reads an integer CPU frequency value from sysfs.
+  bool ReadFreqToInt(const std::string& sysfs_file_name, int* value);
+
+  // Reads the current OS version from /etc/lsb-release and hashes it
+  // to a unsigned 32-bit int.
+  uint32_t GetOsVersionHash();
+
+  // Updates stats, additionally sending them to UMA if enough time has elapsed
+  // since the last report.
+  void UpdateStats(base::TimeTicks now_ticks, base::Time now_wall_time);
+
+  // Invoked periodically by |update_stats_timeout_id_| to call UpdateStats().
+  void HandleUpdateStatsTimeout();
+
+  // Reports zram statistics.
+  bool ReportZram(const base::FilePath& zram_dir);
+
+  // Reads a string from a file and converts it to uint64_t.
+  static bool ReadFileToUint64(const base::FilePath& path, uint64_t* value);
+
+  // VARIABLES
+
+  // Test mode.
+  bool testing_;
+
+  // Whether the uploader is enabled or disabled.
+  bool uploader_active_;
+
+  // Whether or not dbus should be used.
+  // If disabled, we will not collect the frequency of crashes.
+  bool dbus_enabled_;
+
+  // Root of the configuration files to use.
+  std::string config_root_;
+
+  // The metrics library handle.
+  MetricsLibraryInterface* metrics_lib_;
+
+  // Timestamps last network state update.  This timestamp is used to
+  // sample the time from the network going online to going offline so
+  // TimeTicks ensures a monotonically increasing TimeDelta.
+  base::TimeTicks network_state_last_;
+
+  // The last time that UpdateStats() was called.
+  base::TimeTicks last_update_stats_time_;
+
+  // End time of current memuse stat collection interval.
+  double memuse_final_time_;
+
+  // Selects the wait time for the next memory use callback.
+  unsigned int memuse_interval_index_;
+
+  // Contain the most recent disk and vm cumulative stats.
+  uint64_t read_sectors_;
+  uint64_t write_sectors_;
+  struct VmstatRecord vmstats_;
+
+  StatsState stats_state_;
+  double stats_initial_time_;
+
+  // The system "HZ", or frequency of ticks.  Some system data uses ticks as a
+  // unit, and this is used to convert to standard time units.
+  uint32_t ticks_per_second_;
+  // Used internally by GetIncrementalCpuUse() to return the CPU utilization
+  // between calls.
+  uint64_t latest_cpu_use_ticks_;
+
+  // Persistent values and accumulators for crash statistics.
+  scoped_ptr<PersistentInteger> daily_cycle_;
+  scoped_ptr<PersistentInteger> weekly_cycle_;
+  scoped_ptr<PersistentInteger> version_cycle_;
+
+  // Active use accumulated in a day.
+  scoped_ptr<PersistentInteger> daily_active_use_;
+  // Active use accumulated since the latest version update.
+  scoped_ptr<PersistentInteger> version_cumulative_active_use_;
+
+  // The CPU time accumulator.  This contains the CPU time, in milliseconds,
+  // used by the system since the most recent OS version update.
+  scoped_ptr<PersistentInteger> version_cumulative_cpu_use_;
+
+  scoped_ptr<PersistentInteger> user_crash_interval_;
+  scoped_ptr<PersistentInteger> kernel_crash_interval_;
+  scoped_ptr<PersistentInteger> unclean_shutdown_interval_;
+
+  scoped_ptr<PersistentInteger> any_crashes_daily_count_;
+  scoped_ptr<PersistentInteger> any_crashes_weekly_count_;
+  scoped_ptr<PersistentInteger> user_crashes_daily_count_;
+  scoped_ptr<PersistentInteger> user_crashes_weekly_count_;
+  scoped_ptr<PersistentInteger> kernel_crashes_daily_count_;
+  scoped_ptr<PersistentInteger> kernel_crashes_weekly_count_;
+  scoped_ptr<PersistentInteger> kernel_crashes_version_count_;
+  scoped_ptr<PersistentInteger> unclean_shutdowns_daily_count_;
+  scoped_ptr<PersistentInteger> unclean_shutdowns_weekly_count_;
+
+  std::string vmstats_path_;
+  std::string scaling_max_freq_path_;
+  std::string cpuinfo_max_freq_path_;
+
+  base::TimeDelta upload_interval_;
+  std::string server_;
+  std::string metrics_file_;
+
+  scoped_ptr<UploadService> upload_service_;
+};
+
+#endif  // METRICS_METRICS_DAEMON_H_
diff --git a/metricsd/metrics_daemon_main.cc b/metricsd/metrics_daemon_main.cc
new file mode 100644
index 000000000..6c580ba25
--- /dev/null
+++ b/metricsd/metrics_daemon_main.cc
@@ -0,0 +1,80 @@
+// Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <base/at_exit.h>
+#include <base/command_line.h>
+#include <base/logging.h>
+#include <base/strings/string_util.h>
+#include <chromeos/flag_helper.h>
+#include <chromeos/syslog_logging.h>
+
+#include "constants.h"
+#include "metrics_daemon.h"
+
+const char kScalingMaxFreqPath[] =
+    "/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq";
+const char kCpuinfoMaxFreqPath[] =
+    "/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq";
+
+int main(int argc, char** argv) {
+  DEFINE_bool(daemon, true, "run as daemon (use -nodaemon for debugging)");
+
+  // The uploader is disabled by default on ChromeOS as Chrome is responsible
+  // for sending the metrics.
+  DEFINE_bool(uploader, false, "activate the uploader");
+
+  // Upload the metrics once and exit. (used for testing)
+  DEFINE_bool(uploader_test,
+              false,
+              "run the uploader once and exit");
+
+  // Enable dbus.
+  DEFINE_bool(withdbus, true, "Enable dbus");
+
+  // Upload Service flags.
+  DEFINE_int32(upload_interval_secs,
+               1800,
+               "Interval at which metrics_daemon sends the metrics. (needs "
+               "-uploader)");
+  DEFINE_string(server,
+                metrics::kMetricsServer,
+                "Server to upload the metrics to. (needs -uploader)");
+  DEFINE_string(metrics_file,
+                metrics::kMetricsEventsFilePath,
+                "File to use as a proxy for uploading the metrics");
+  DEFINE_string(config_root,
+                "/", "Root of the configuration files (testing only)");
+
+  chromeos::FlagHelper::Init(argc, argv, "Chromium OS Metrics Daemon");
+
+  // Also log to stderr when not running as daemon.
+  chromeos::InitLog(chromeos::kLogToSyslog | chromeos::kLogHeader |
+                    (FLAGS_daemon ? 0 : chromeos::kLogToStderr));
+
+  if (FLAGS_daemon && daemon(0, 0) != 0) {
+    return errno;
+  }
+
+  MetricsLibrary metrics_lib;
+  metrics_lib.Init();
+  MetricsDaemon daemon;
+  daemon.Init(FLAGS_uploader_test,
+              FLAGS_uploader | FLAGS_uploader_test,
+              FLAGS_withdbus,
+              &metrics_lib,
+              "/proc/vmstat",
+              kScalingMaxFreqPath,
+              kCpuinfoMaxFreqPath,
+              base::TimeDelta::FromSeconds(FLAGS_upload_interval_secs),
+              FLAGS_server,
+              FLAGS_metrics_file,
+              FLAGS_config_root);
+
+  if (FLAGS_uploader_test) {
+    daemon.RunUploaderTest();
+    return 0;
+  }
+
+  daemon.Run();
+}
diff --git a/metricsd/metrics_daemon_test.cc b/metricsd/metrics_daemon_test.cc
new file mode 100644
index 000000000..5aa7ab88e
--- /dev/null
+++ b/metricsd/metrics_daemon_test.cc
@@ -0,0 +1,388 @@
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <inttypes.h>
+#include <utime.h>
+
+#include <string>
+#include <vector>
+
+#include <base/at_exit.h>
+#include <base/files/file_util.h>
+#include <base/strings/string_number_conversions.h>
+#include <base/strings/stringprintf.h>
+#include <chromeos/dbus/service_constants.h>
+#include <gtest/gtest.h>
+
+#include "metrics_daemon.h"
+#include "metrics_library_mock.h"
+#include "persistent_integer_mock.h"
+
+using base::FilePath;
+using base::StringPrintf;
+using base::Time;
+using base::TimeDelta;
+using base::TimeTicks;
+using std::string;
+using std::vector;
+using ::testing::_;
+using ::testing::AnyNumber;
+using ::testing::AtLeast;
+using ::testing::Return;
+using ::testing::StrictMock;
+using chromeos_metrics::PersistentIntegerMock;
+
+static const char kFakeDiskStatsName[] = "fake-disk-stats";
+static const char kFakeDiskStatsFormat[] =
+    "    1793     1788    %" PRIu64 "   105580    "
+    "    196      175     %" PRIu64 "    30290    "
+    "    0    44060   135850\n";
+static const uint64_t kFakeReadSectors[] = {80000, 100000};
+static const uint64_t kFakeWriteSectors[] = {3000, 4000};
+
+static const char kFakeVmStatsName[] = "fake-vm-stats";
+static const char kFakeScalingMaxFreqPath[] = "fake-scaling-max-freq";
+static const char kFakeCpuinfoMaxFreqPath[] = "fake-cpuinfo-max-freq";
+
+class MetricsDaemonTest : public testing::Test {
+ protected:
+  std::string kFakeDiskStats0;
+  std::string kFakeDiskStats1;
+
+  virtual void SetUp() {
+    kFakeDiskStats0 = base::StringPrintf(kFakeDiskStatsFormat,
+                                           kFakeReadSectors[0],
+                                           kFakeWriteSectors[0]);
+    kFakeDiskStats1 = base::StringPrintf(kFakeDiskStatsFormat,
+                                           kFakeReadSectors[1],
+                                           kFakeWriteSectors[1]);
+    CreateFakeDiskStatsFile(kFakeDiskStats0.c_str());
+    CreateUint64ValueFile(base::FilePath(kFakeCpuinfoMaxFreqPath), 10000000);
+    CreateUint64ValueFile(base::FilePath(kFakeScalingMaxFreqPath), 10000000);
+
+    chromeos_metrics::PersistentInteger::SetTestingMode(true);
+    daemon_.Init(true,
+                 false,
+                 &metrics_lib_,
+                 kFakeDiskStatsName,
+                 kFakeVmStatsName,
+                 kFakeScalingMaxFreqPath,
+                 kFakeCpuinfoMaxFreqPath,
+                 base::TimeDelta::FromMinutes(30),
+                 kMetricsServer,
+                 kMetricsFilePath,
+                 "/");
+
+    // Replace original persistent values with mock ones.
+    daily_active_use_mock_ =
+        new StrictMock<PersistentIntegerMock>("1.mock");
+    daemon_.daily_active_use_.reset(daily_active_use_mock_);
+
+    kernel_crash_interval_mock_ =
+        new StrictMock<PersistentIntegerMock>("2.mock");
+    daemon_.kernel_crash_interval_.reset(kernel_crash_interval_mock_);
+
+    user_crash_interval_mock_ =
+        new StrictMock<PersistentIntegerMock>("3.mock");
+    daemon_.user_crash_interval_.reset(user_crash_interval_mock_);
+
+    unclean_shutdown_interval_mock_ =
+        new StrictMock<PersistentIntegerMock>("4.mock");
+    daemon_.unclean_shutdown_interval_.reset(unclean_shutdown_interval_mock_);
+  }
+
+  virtual void TearDown() {
+    EXPECT_EQ(0, unlink(kFakeDiskStatsName));
+    EXPECT_EQ(0, unlink(kFakeScalingMaxFreqPath));
+    EXPECT_EQ(0, unlink(kFakeCpuinfoMaxFreqPath));
+  }
+
+  // Adds active use aggregation counters update expectations that the
+  // specified count will be added.
+  void ExpectActiveUseUpdate(int count) {
+    EXPECT_CALL(*daily_active_use_mock_, Add(count))
+        .Times(1)
+        .RetiresOnSaturation();
+    EXPECT_CALL(*kernel_crash_interval_mock_, Add(count))
+        .Times(1)
+        .RetiresOnSaturation();
+    EXPECT_CALL(*user_crash_interval_mock_, Add(count))
+        .Times(1)
+        .RetiresOnSaturation();
+  }
+
+  // As above, but ignore values of counter updates.
+  void IgnoreActiveUseUpdate() {
+    EXPECT_CALL(*daily_active_use_mock_, Add(_))
+        .Times(1)
+        .RetiresOnSaturation();
+    EXPECT_CALL(*kernel_crash_interval_mock_, Add(_))
+        .Times(1)
+        .RetiresOnSaturation();
+    EXPECT_CALL(*user_crash_interval_mock_, Add(_))
+        .Times(1)
+        .RetiresOnSaturation();
+  }
+
+  // Adds a metrics library mock expectation that the specified metric
+  // will be generated.
+  void ExpectSample(const std::string& name, int sample) {
+    EXPECT_CALL(metrics_lib_, SendToUMA(name, sample, _, _, _))
+        .Times(1)
+        .WillOnce(Return(true))
+        .RetiresOnSaturation();
+  }
+
+  // Creates a new DBus signal message with zero or more string arguments.
+  // The message can be deallocated through DeleteDBusMessage.
+  //
+  // |path| is the object emitting the signal.
+  // |interface| is the interface the signal is emitted from.
+  // |name| is the name of the signal.
+  // |arg_values| contains the values of the string arguments.
+  DBusMessage* NewDBusSignalString(const string& path,
+                                   const string& interface,
+                                   const string& name,
+                                   const vector<string>& arg_values) {
+    DBusMessage* msg = dbus_message_new_signal(path.c_str(),
+                                               interface.c_str(),
+                                               name.c_str());
+    DBusMessageIter iter;
+    dbus_message_iter_init_append(msg, &iter);
+    for (vector<string>::const_iterator it = arg_values.begin();
+         it != arg_values.end(); ++it) {
+      const char* str_value = it->c_str();
+      dbus_message_iter_append_basic(&iter, DBUS_TYPE_STRING, &str_value);
+    }
+    return msg;
+  }
+
+  // Deallocates the DBus message |msg| previously allocated through
+  // dbus_message_new*.
+  void DeleteDBusMessage(DBusMessage* msg) {
+    dbus_message_unref(msg);
+  }
+
+  // Creates or overwrites an input file containing fake disk stats.
+  void CreateFakeDiskStatsFile(const char* fake_stats) {
+    if (unlink(kFakeDiskStatsName) < 0) {
+      EXPECT_EQ(errno, ENOENT);
+    }
+    FILE* f = fopen(kFakeDiskStatsName, "w");
+    EXPECT_EQ(1, fwrite(fake_stats, strlen(fake_stats), 1, f));
+    EXPECT_EQ(0, fclose(f));
+  }
+
+  // Creates or overwrites the file in |path| so that it contains the printable
+  // representation of |value|.
+  void CreateUint64ValueFile(const base::FilePath& path, uint64_t value) {
+    base::DeleteFile(path, false);
+    std::string value_string = base::Uint64ToString(value);
+    ASSERT_EQ(value_string.length(),
+              base::WriteFile(path, value_string.c_str(),
+                              value_string.length()));
+  }
+
+  // The MetricsDaemon under test.
+  MetricsDaemon daemon_;
+
+  // Mocks. They are strict mock so that all unexpected
+  // calls are marked as failures.
+  StrictMock<MetricsLibraryMock> metrics_lib_;
+  StrictMock<PersistentIntegerMock>* daily_active_use_mock_;
+  StrictMock<PersistentIntegerMock>* kernel_crash_interval_mock_;
+  StrictMock<PersistentIntegerMock>* user_crash_interval_mock_;
+  StrictMock<PersistentIntegerMock>* unclean_shutdown_interval_mock_;
+};
+
+TEST_F(MetricsDaemonTest, CheckSystemCrash) {
+  static const char kKernelCrashDetected[] = "test-kernel-crash-detected";
+  EXPECT_FALSE(daemon_.CheckSystemCrash(kKernelCrashDetected));
+
+  base::FilePath crash_detected(kKernelCrashDetected);
+  base::WriteFile(crash_detected, "", 0);
+  EXPECT_TRUE(base::PathExists(crash_detected));
+  EXPECT_TRUE(daemon_.CheckSystemCrash(kKernelCrashDetected));
+  EXPECT_FALSE(base::PathExists(crash_detected));
+  EXPECT_FALSE(daemon_.CheckSystemCrash(kKernelCrashDetected));
+  EXPECT_FALSE(base::PathExists(crash_detected));
+  base::DeleteFile(crash_detected, false);
+}
+
+TEST_F(MetricsDaemonTest, MessageFilter) {
+  // Ignore calls to SendToUMA.
+  EXPECT_CALL(metrics_lib_, SendToUMA(_, _, _, _, _)).Times(AnyNumber());
+
+  DBusMessage* msg = dbus_message_new(DBUS_MESSAGE_TYPE_METHOD_CALL);
+  DBusHandlerResult res =
+      MetricsDaemon::MessageFilter(/* connection */ nullptr, msg, &daemon_);
+  EXPECT_EQ(DBUS_HANDLER_RESULT_NOT_YET_HANDLED, res);
+  DeleteDBusMessage(msg);
+
+  IgnoreActiveUseUpdate();
+  vector<string> signal_args;
+  msg = NewDBusSignalString("/",
+                            "org.chromium.CrashReporter",
+                            "UserCrash",
+                            signal_args);
+  res = MetricsDaemon::MessageFilter(/* connection */ nullptr, msg, &daemon_);
+  EXPECT_EQ(DBUS_HANDLER_RESULT_HANDLED, res);
+  DeleteDBusMessage(msg);
+
+  signal_args.clear();
+  signal_args.push_back("randomstate");
+  signal_args.push_back("bob");  // arbitrary username
+  msg = NewDBusSignalString("/",
+                            "org.chromium.UnknownService.Manager",
+                            "StateChanged",
+                            signal_args);
+  res = MetricsDaemon::MessageFilter(/* connection */ nullptr, msg, &daemon_);
+  EXPECT_EQ(DBUS_HANDLER_RESULT_NOT_YET_HANDLED, res);
+  DeleteDBusMessage(msg);
+}
+
+TEST_F(MetricsDaemonTest, SendSample) {
+  ExpectSample("Dummy.Metric", 3);
+  daemon_.SendSample("Dummy.Metric", /* sample */ 3,
+                     /* min */ 1, /* max */ 100, /* buckets */ 50);
+}
+
+TEST_F(MetricsDaemonTest, ReportDiskStats) {
+  uint64_t read_sectors_now, write_sectors_now;
+  CreateFakeDiskStatsFile(kFakeDiskStats1.c_str());
+  daemon_.DiskStatsReadStats(&read_sectors_now, &write_sectors_now);
+  EXPECT_EQ(read_sectors_now, kFakeReadSectors[1]);
+  EXPECT_EQ(write_sectors_now, kFakeWriteSectors[1]);
+
+  MetricsDaemon::StatsState s_state = daemon_.stats_state_;
+  EXPECT_CALL(metrics_lib_,
+              SendToUMA(_, (kFakeReadSectors[1] - kFakeReadSectors[0]) / 30,
+                        _, _, _));
+  EXPECT_CALL(metrics_lib_,
+              SendToUMA(_, (kFakeWriteSectors[1] - kFakeWriteSectors[0]) / 30,
+                        _, _, _));
+  EXPECT_CALL(metrics_lib_, SendEnumToUMA(_, _, _));  // SendCpuThrottleMetrics
+  daemon_.StatsCallback();
+  EXPECT_TRUE(s_state != daemon_.stats_state_);
+}
+
+TEST_F(MetricsDaemonTest, ProcessMeminfo) {
+  string meminfo =
+      "MemTotal:        2000000 kB\nMemFree:          500000 kB\n"
+      "Buffers:         1000000 kB\nCached:           213652 kB\n"
+      "SwapCached:            0 kB\nActive:           133400 kB\n"
+      "Inactive:         183396 kB\nActive(anon):      92984 kB\n"
+      "Inactive(anon):    58860 kB\nActive(file):      40416 kB\n"
+      "Inactive(file):   124536 kB\nUnevictable:           0 kB\n"
+      "Mlocked:               0 kB\nSwapTotal:             0 kB\n"
+      "SwapFree:              0 kB\nDirty:                40 kB\n"
+      "Writeback:             0 kB\nAnonPages:         92652 kB\n"
+      "Mapped:            59716 kB\nShmem:             59196 kB\n"
+      "Slab:              16656 kB\nSReclaimable:       6132 kB\n"
+      "SUnreclaim:        10524 kB\nKernelStack:        1648 kB\n"
+      "PageTables:         2780 kB\nNFS_Unstable:          0 kB\n"
+      "Bounce:                0 kB\nWritebackTmp:          0 kB\n"
+      "CommitLimit:      970656 kB\nCommitted_AS:    1260528 kB\n"
+      "VmallocTotal:     122880 kB\nVmallocUsed:       12144 kB\n"
+      "VmallocChunk:     103824 kB\nDirectMap4k:        9636 kB\n"
+      "DirectMap2M:     1955840 kB\n";
+
+  // All enum calls must report percents.
+  EXPECT_CALL(metrics_lib_, SendEnumToUMA(_, _, 100)).Times(AtLeast(1));
+  // Check that MemFree is correctly computed at 25%.
+  EXPECT_CALL(metrics_lib_, SendEnumToUMA("Platform.MeminfoMemFree", 25, 100))
+      .Times(AtLeast(1));
+  // Check that we call SendToUma at least once (log histogram).
+  EXPECT_CALL(metrics_lib_, SendToUMA(_, _, _, _, _))
+      .Times(AtLeast(1));
+  // Make sure we don't report fields not in the list.
+  EXPECT_CALL(metrics_lib_, SendToUMA("Platform.MeminfoMlocked", _, _, _, _))
+      .Times(0);
+  EXPECT_CALL(metrics_lib_, SendEnumToUMA("Platform.MeminfoMlocked", _, _))
+      .Times(0);
+  EXPECT_TRUE(daemon_.ProcessMeminfo(meminfo));
+}
+
+TEST_F(MetricsDaemonTest, ProcessMeminfo2) {
+  string meminfo = "MemTotal:        2000000 kB\nMemFree:         1000000 kB\n";
+  // Not enough fields.
+  EXPECT_FALSE(daemon_.ProcessMeminfo(meminfo));
+}
+
+TEST_F(MetricsDaemonTest, ParseVmStats) {
+  static char kVmStats[] = "pswpin 1345\npswpout 8896\n"
+    "foo 100\nbar 200\npgmajfault 42\netcetc 300\n";
+  struct MetricsDaemon::VmstatRecord stats;
+  EXPECT_TRUE(daemon_.VmStatsParseStats(kVmStats, &stats));
+  EXPECT_EQ(stats.page_faults_, 42);
+  EXPECT_EQ(stats.swap_in_, 1345);
+  EXPECT_EQ(stats.swap_out_, 8896);
+}
+
+TEST_F(MetricsDaemonTest, ReadFreqToInt) {
+  const int fake_scaled_freq = 1666999;
+  const int fake_max_freq = 2000000;
+  int scaled_freq = 0;
+  int max_freq = 0;
+  CreateUint64ValueFile(base::FilePath(kFakeScalingMaxFreqPath),
+                        fake_scaled_freq);
+  CreateUint64ValueFile(base::FilePath(kFakeCpuinfoMaxFreqPath), fake_max_freq);
+  EXPECT_TRUE(daemon_.testing_);
+  EXPECT_TRUE(daemon_.ReadFreqToInt(kFakeScalingMaxFreqPath, &scaled_freq));
+  EXPECT_TRUE(daemon_.ReadFreqToInt(kFakeCpuinfoMaxFreqPath, &max_freq));
+  EXPECT_EQ(fake_scaled_freq, scaled_freq);
+  EXPECT_EQ(fake_max_freq, max_freq);
+}
+
+TEST_F(MetricsDaemonTest, SendCpuThrottleMetrics) {
+  CreateUint64ValueFile(base::FilePath(kFakeCpuinfoMaxFreqPath), 2001000);
+  // Test the 101% and 100% cases.
+  CreateUint64ValueFile(base::FilePath(kFakeScalingMaxFreqPath), 2001000);
+  EXPECT_TRUE(daemon_.testing_);
+  EXPECT_CALL(metrics_lib_, SendEnumToUMA(_, 101, 101));
+  daemon_.SendCpuThrottleMetrics();
+  CreateUint64ValueFile(base::FilePath(kFakeScalingMaxFreqPath), 2000000);
+  EXPECT_CALL(metrics_lib_, SendEnumToUMA(_, 100, 101));
+  daemon_.SendCpuThrottleMetrics();
+}
+
+TEST_F(MetricsDaemonTest, SendZramMetrics) {
+  EXPECT_TRUE(daemon_.testing_);
+
+  // |compr_data_size| is the size in bytes of compressed data.
+  const uint64_t compr_data_size = 50 * 1000 * 1000;
+  // The constant '3' is a realistic but random choice.
+  // |orig_data_size| does not include zero pages.
+  const uint64_t orig_data_size = compr_data_size * 3;
+  const uint64_t page_size = 4096;
+  const uint64_t zero_pages = 10 * 1000 * 1000 / page_size;
+
+  CreateUint64ValueFile(base::FilePath(MetricsDaemon::kComprDataSizeName),
+                        compr_data_size);
+  CreateUint64ValueFile(base::FilePath(MetricsDaemon::kOrigDataSizeName),
+                        orig_data_size);
+  CreateUint64ValueFile(base::FilePath(MetricsDaemon::kZeroPagesName),
+                        zero_pages);
+
+  const uint64_t real_orig_size = orig_data_size + zero_pages * page_size;
+  const uint64_t zero_ratio_percent =
+      zero_pages * page_size * 100 / real_orig_size;
+  // Ratio samples are in percents.
+  const uint64_t actual_ratio_sample = real_orig_size * 100 / compr_data_size;
+
+  EXPECT_CALL(metrics_lib_, SendToUMA(_, compr_data_size >> 20, _, _, _));
+  EXPECT_CALL(metrics_lib_,
+              SendToUMA(_, (real_orig_size - compr_data_size) >> 20, _, _, _));
+  EXPECT_CALL(metrics_lib_, SendToUMA(_, actual_ratio_sample, _, _, _));
+  EXPECT_CALL(metrics_lib_, SendToUMA(_, zero_pages, _, _, _));
+  EXPECT_CALL(metrics_lib_, SendToUMA(_, zero_ratio_percent, _, _, _));
+
+  EXPECT_TRUE(daemon_.ReportZram(base::FilePath(".")));
+}
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+
+  return RUN_ALL_TESTS();
+}
diff --git a/metricsd/metrics_library.cc b/metricsd/metrics_library.cc
new file mode 100644
index 000000000..f777f2823
--- /dev/null
+++ b/metricsd/metrics_library.cc
@@ -0,0 +1,172 @@
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "metrics/metrics_library.h"
+
+#include <base/logging.h>
+#include <base/strings/stringprintf.h>
+#include <errno.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+
+#include <cstdio>
+#include <cstring>
+
+#include "constants.h"
+#include "serialization/metric_sample.h"
+#include "serialization/serialization_utils.h"
+
+static const char kCrosEventHistogramName[] = "Platform.CrOSEvent";
+static const int kCrosEventHistogramMax = 100;
+
+/* Add new cros events here.
+ *
+ * The index of the event is sent in the message, so please do not
+ * reorder the names.
+ */
+static const char *kCrosEventNames[] = {
+  "ModemManagerCommandSendFailure",  // 0
+  "HwWatchdogReboot",  // 1
+  "Cras.NoCodecsFoundAtBoot",  // 2
+  "Chaps.DatabaseCorrupted",  // 3
+  "Chaps.DatabaseRepairFailure",  // 4
+  "Chaps.DatabaseCreateFailure",  // 5
+  "Attestation.OriginSpecificExhausted",  // 6
+  "SpringPowerSupply.Original.High",  // 7
+  "SpringPowerSupply.Other.High",  // 8
+  "SpringPowerSupply.Original.Low",  // 9
+  "SpringPowerSupply.ChargerIdle",  // 10
+  "TPM.NonZeroDictionaryAttackCounter",  // 11
+  "TPM.EarlyResetDuringCommand",  // 12
+};
+
+time_t MetricsLibrary::cached_enabled_time_ = 0;
+bool MetricsLibrary::cached_enabled_ = false;
+
+MetricsLibrary::MetricsLibrary() : consent_file_(metrics::kConsentFilePath) {}
+MetricsLibrary::~MetricsLibrary() {}
+
+// We take buffer and buffer_size as parameters in order to simplify testing
+// of various alignments of the |device_name| with |buffer_size|.
+bool MetricsLibrary::IsDeviceMounted(const char* device_name,
+                                     const char* mounts_file,
+                                     char* buffer,
+                                     int buffer_size,
+                                     bool* result) {
+  if (buffer == nullptr || buffer_size < 1)
+    return false;
+  int mounts_fd = open(mounts_file, O_RDONLY);
+  if (mounts_fd < 0)
+    return false;
+  // match_offset describes:
+  //   -1 -- not beginning of line
+  //   0..strlen(device_name)-1 -- this offset in device_name is next to match
+  //   strlen(device_name) -- matched full name, just need a space.
+  int match_offset = 0;
+  bool match = false;
+  while (!match) {
+    int read_size = read(mounts_fd, buffer, buffer_size);
+    if (read_size <= 0) {
+      if (errno == -EINTR)
+        continue;
+      break;
+    }
+    for (int i = 0; i < read_size; ++i) {
+      if (buffer[i] == '\n') {
+        match_offset = 0;
+        continue;
+      }
+      if (match_offset < 0) {
+        continue;
+      }
+      if (device_name[match_offset] == '\0') {
+        if (buffer[i] == ' ') {
+          match = true;
+          break;
+        }
+        match_offset = -1;
+        continue;
+      }
+
+      if (buffer[i] == device_name[match_offset]) {
+        ++match_offset;
+      } else {
+        match_offset = -1;
+      }
+    }
+  }
+  close(mounts_fd);
+  *result = match;
+  return true;
+}
+
+bool MetricsLibrary::IsGuestMode() {
+  char buffer[256];
+  bool result = false;
+  if (!IsDeviceMounted("guestfs",
+                       "/proc/mounts",
+                       buffer,
+                       sizeof(buffer),
+                       &result)) {
+    return false;
+  }
+  return result && (access("/var/run/state/logged-in", F_OK) == 0);
+}
+
+bool MetricsLibrary::AreMetricsEnabled() {
+  static struct stat stat_buffer;
+  time_t this_check_time = time(nullptr);
+  if (this_check_time != cached_enabled_time_) {
+    cached_enabled_time_ = this_check_time;
+    cached_enabled_ = stat(consent_file_.c_str(), &stat_buffer) >= 0;
+  }
+  return cached_enabled_;
+}
+
+void MetricsLibrary::Init() {
+  uma_events_file_ = metrics::kMetricsEventsFilePath;
+}
+
+bool MetricsLibrary::SendToUMA(const std::string& name,
+                               int sample,
+                               int min,
+                               int max,
+                               int nbuckets) {
+  return metrics::SerializationUtils::WriteMetricToFile(
+      *metrics::MetricSample::HistogramSample(name, sample, min, max, nbuckets)
+           .get(),
+      metrics::kMetricsEventsFilePath);
+}
+
+bool MetricsLibrary::SendEnumToUMA(const std::string& name, int sample,
+                                   int max) {
+  return metrics::SerializationUtils::WriteMetricToFile(
+      *metrics::MetricSample::LinearHistogramSample(name, sample, max).get(),
+      metrics::kMetricsEventsFilePath);
+}
+
+bool MetricsLibrary::SendSparseToUMA(const std::string& name, int sample) {
+  return metrics::SerializationUtils::WriteMetricToFile(
+      *metrics::MetricSample::SparseHistogramSample(name, sample).get(),
+      metrics::kMetricsEventsFilePath);
+}
+
+bool MetricsLibrary::SendUserActionToUMA(const std::string& action) {
+  return metrics::SerializationUtils::WriteMetricToFile(
+      *metrics::MetricSample::UserActionSample(action).get(), metrics::kMetricsEventsFilePath);
+}
+
+bool MetricsLibrary::SendCrashToUMA(const char *crash_kind) {
+  return metrics::SerializationUtils::WriteMetricToFile(
+      *metrics::MetricSample::CrashSample(crash_kind).get(), metrics::kMetricsEventsFilePath);
+}
+
+bool MetricsLibrary::SendCrosEventToUMA(const std::string& event) {
+  for (size_t i = 0; i < arraysize(kCrosEventNames); i++) {
+    if (strcmp(event.c_str(), kCrosEventNames[i]) == 0) {
+      return SendEnumToUMA(kCrosEventHistogramName, i, kCrosEventHistogramMax);
+    }
+  }
+  return false;
+}
diff --git a/metricsd/metrics_library_mock.h b/metricsd/metrics_library_mock.h
new file mode 100644
index 000000000..99892bfa0
--- /dev/null
+++ b/metricsd/metrics_library_mock.h
@@ -0,0 +1,29 @@
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_METRICS_LIBRARY_MOCK_H_
+#define METRICS_METRICS_LIBRARY_MOCK_H_
+
+#include <string>
+
+#include "metrics/metrics_library.h"
+
+#include <gmock/gmock.h>
+
+class MetricsLibraryMock : public MetricsLibraryInterface {
+ public:
+  bool metrics_enabled_ = true;
+
+  MOCK_METHOD0(Init, void());
+  MOCK_METHOD5(SendToUMA, bool(const std::string& name, int sample,
+                               int min, int max, int nbuckets));
+  MOCK_METHOD3(SendEnumToUMA, bool(const std::string& name, int sample,
+                                   int max));
+  MOCK_METHOD2(SendSparseToUMA, bool(const std::string& name, int sample));
+  MOCK_METHOD1(SendUserActionToUMA, bool(const std::string& action));
+
+  bool AreMetricsEnabled() override {return metrics_enabled_;};
+};
+
+#endif  // METRICS_METRICS_LIBRARY_MOCK_H_
diff --git a/metricsd/metrics_library_test.cc b/metricsd/metrics_library_test.cc
new file mode 100644
index 000000000..7ede303c8
--- /dev/null
+++ b/metricsd/metrics_library_test.cc
@@ -0,0 +1,214 @@
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <cstring>
+
+#include <base/files/file_util.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <policy/mock_device_policy.h>
+#include <policy/libpolicy.h>
+
+#include "metrics/c_metrics_library.h"
+#include "metrics/metrics_library.h"
+
+using base::FilePath;
+using ::testing::_;
+using ::testing::Return;
+using ::testing::AnyNumber;
+
+static const FilePath kTestUMAEventsFile("test-uma-events");
+static const char kTestMounts[] = "test-mounts";
+
+ACTION_P(SetMetricsPolicy, enabled) {
+  *arg0 = enabled;
+  return true;
+}
+
+class MetricsLibraryTest : public testing::Test {
+ protected:
+  virtual void SetUp() {
+    EXPECT_TRUE(lib_.uma_events_file_.empty());
+    lib_.Init();
+    EXPECT_FALSE(lib_.uma_events_file_.empty());
+    lib_.uma_events_file_ = kTestUMAEventsFile.value();
+    EXPECT_EQ(0, WriteFile(kTestUMAEventsFile, "", 0));
+    device_policy_ = new policy::MockDevicePolicy();
+    EXPECT_CALL(*device_policy_, LoadPolicy())
+        .Times(AnyNumber())
+        .WillRepeatedly(Return(true));
+    EXPECT_CALL(*device_policy_, GetMetricsEnabled(_))
+        .Times(AnyNumber())
+        .WillRepeatedly(SetMetricsPolicy(true));
+    provider_ = new policy::PolicyProvider(device_policy_);
+    lib_.SetPolicyProvider(provider_);
+    // Defeat metrics enabled caching between tests.
+    lib_.cached_enabled_time_ = 0;
+  }
+
+  virtual void TearDown() {
+    base::DeleteFile(FilePath(kTestMounts), false);
+    base::DeleteFile(kTestUMAEventsFile, false);
+  }
+
+  void VerifyEnabledCacheHit(bool to_value);
+  void VerifyEnabledCacheEviction(bool to_value);
+
+  MetricsLibrary lib_;
+  policy::MockDevicePolicy* device_policy_;
+  policy::PolicyProvider* provider_;
+};
+
+TEST_F(MetricsLibraryTest, IsDeviceMounted) {
+  static const char kTestContents[] =
+      "0123456789abcde 0123456789abcde\nguestfs foo bar\n";
+  char buffer[1024];
+  int block_sizes[] = { 1, 2, 3, 4, 5, 6, 8, 12, 14, 16, 32, 1024 };
+  bool result;
+  EXPECT_FALSE(lib_.IsDeviceMounted("guestfs",
+                                    "nonexistent",
+                                    buffer,
+                                    1,
+                                    &result));
+  ASSERT_TRUE(base::WriteFile(base::FilePath(kTestMounts),
+                              kTestContents,
+                              strlen(kTestContents)));
+  EXPECT_FALSE(lib_.IsDeviceMounted("guestfs",
+                                    kTestMounts,
+                                    buffer,
+                                    0,
+                                    &result));
+  for (size_t i = 0; i < arraysize(block_sizes); ++i) {
+    EXPECT_TRUE(lib_.IsDeviceMounted("0123456789abcde",
+                                     kTestMounts,
+                                     buffer,
+                                     block_sizes[i],
+                                     &result));
+    EXPECT_TRUE(result);
+    EXPECT_TRUE(lib_.IsDeviceMounted("guestfs",
+                                     kTestMounts,
+                                     buffer,
+                                     block_sizes[i],
+                                     &result));
+    EXPECT_TRUE(result);
+    EXPECT_TRUE(lib_.IsDeviceMounted("0123456",
+                                     kTestMounts,
+                                     buffer,
+                                     block_sizes[i],
+                                     &result));
+    EXPECT_FALSE(result);
+    EXPECT_TRUE(lib_.IsDeviceMounted("9abcde",
+                                     kTestMounts,
+                                     buffer,
+                                     block_sizes[i],
+                                     &result));
+    EXPECT_FALSE(result);
+    EXPECT_TRUE(lib_.IsDeviceMounted("foo",
+                                     kTestMounts,
+                                     buffer,
+                                     block_sizes[i],
+                                     &result));
+    EXPECT_FALSE(result);
+    EXPECT_TRUE(lib_.IsDeviceMounted("bar",
+                                     kTestMounts,
+                                     buffer,
+                                     block_sizes[i],
+                                     &result));
+    EXPECT_FALSE(result);
+  }
+}
+
+TEST_F(MetricsLibraryTest, AreMetricsEnabledFalse) {
+  EXPECT_CALL(*device_policy_, GetMetricsEnabled(_))
+      .WillOnce(SetMetricsPolicy(false));
+  EXPECT_FALSE(lib_.AreMetricsEnabled());
+}
+
+TEST_F(MetricsLibraryTest, AreMetricsEnabledTrue) {
+  EXPECT_TRUE(lib_.AreMetricsEnabled());
+}
+
+void MetricsLibraryTest::VerifyEnabledCacheHit(bool to_value) {
+  // We might step from one second to the next one time, but not 100
+  // times in a row.
+  for (int i = 0; i < 100; ++i) {
+    lib_.cached_enabled_time_ = 0;
+    EXPECT_CALL(*device_policy_, GetMetricsEnabled(_))
+        .WillOnce(SetMetricsPolicy(!to_value));
+    ASSERT_EQ(!to_value, lib_.AreMetricsEnabled());
+    ON_CALL(*device_policy_, GetMetricsEnabled(_))
+        .WillByDefault(SetMetricsPolicy(to_value));
+    if (lib_.AreMetricsEnabled() == !to_value)
+      return;
+  }
+  ADD_FAILURE() << "Did not see evidence of caching";
+}
+
+void MetricsLibraryTest::VerifyEnabledCacheEviction(bool to_value) {
+  lib_.cached_enabled_time_ = 0;
+  EXPECT_CALL(*device_policy_, GetMetricsEnabled(_))
+      .WillOnce(SetMetricsPolicy(!to_value));
+  ASSERT_EQ(!to_value, lib_.AreMetricsEnabled());
+  EXPECT_CALL(*device_policy_, GetMetricsEnabled(_))
+      .WillOnce(SetMetricsPolicy(to_value));
+  ASSERT_LT(abs(static_cast<int>(time(nullptr) - lib_.cached_enabled_time_)),
+            5);
+  // Sleep one second (or cheat to be faster).
+  --lib_.cached_enabled_time_;
+  ASSERT_EQ(to_value, lib_.AreMetricsEnabled());
+}
+
+TEST_F(MetricsLibraryTest, AreMetricsEnabledCaching) {
+  VerifyEnabledCacheHit(false);
+  VerifyEnabledCacheHit(true);
+  VerifyEnabledCacheEviction(false);
+  VerifyEnabledCacheEviction(true);
+}
+
+class CMetricsLibraryTest : public testing::Test {
+ protected:
+  virtual void SetUp() {
+    lib_ = CMetricsLibraryNew();
+    MetricsLibrary& ml = *reinterpret_cast<MetricsLibrary*>(lib_);
+    EXPECT_TRUE(ml.uma_events_file_.empty());
+    CMetricsLibraryInit(lib_);
+    EXPECT_FALSE(ml.uma_events_file_.empty());
+    ml.uma_events_file_ = kTestUMAEventsFile.value();
+    EXPECT_EQ(0, WriteFile(kTestUMAEventsFile, "", 0));
+    device_policy_ = new policy::MockDevicePolicy();
+    EXPECT_CALL(*device_policy_, LoadPolicy())
+        .Times(AnyNumber())
+        .WillRepeatedly(Return(true));
+    EXPECT_CALL(*device_policy_, GetMetricsEnabled(_))
+        .Times(AnyNumber())
+        .WillRepeatedly(SetMetricsPolicy(true));
+    provider_ = new policy::PolicyProvider(device_policy_);
+    ml.SetPolicyProvider(provider_);
+    reinterpret_cast<MetricsLibrary*>(lib_)->cached_enabled_time_ = 0;
+  }
+
+  virtual void TearDown() {
+    CMetricsLibraryDelete(lib_);
+    base::DeleteFile(kTestUMAEventsFile, false);
+  }
+
+  CMetricsLibrary lib_;
+  policy::MockDevicePolicy* device_policy_;
+  policy::PolicyProvider* provider_;
+};
+
+TEST_F(CMetricsLibraryTest, AreMetricsEnabledFalse) {
+  EXPECT_CALL(*device_policy_, GetMetricsEnabled(_))
+      .WillOnce(SetMetricsPolicy(false));
+  EXPECT_FALSE(CMetricsLibraryAreMetricsEnabled(lib_));
+}
+
+TEST_F(CMetricsLibraryTest, AreMetricsEnabledTrue) {
+  EXPECT_TRUE(CMetricsLibraryAreMetricsEnabled(lib_));
+}
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
diff --git a/metricsd/persistent_integer.cc b/metricsd/persistent_integer.cc
new file mode 100644
index 000000000..0dcd52af1
--- /dev/null
+++ b/metricsd/persistent_integer.cc
@@ -0,0 +1,96 @@
+// Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "persistent_integer.h"
+
+#include <fcntl.h>
+
+#include <base/logging.h>
+#include <base/posix/eintr_wrapper.h>
+
+#include "constants.h"
+#include "metrics/metrics_library.h"
+
+
+namespace chromeos_metrics {
+
+// Static class member instantiation.
+bool PersistentInteger::testing_ = false;
+
+PersistentInteger::PersistentInteger(const std::string& name) :
+      value_(0),
+      version_(kVersion),
+      name_(name),
+      synced_(false) {
+  if (testing_) {
+    backing_file_name_ = name_;
+  } else {
+    backing_file_name_ = metrics::kMetricsDirectory + name_;
+  }
+}
+
+PersistentInteger::~PersistentInteger() {}
+
+void PersistentInteger::Set(int64_t value) {
+  value_ = value;
+  Write();
+}
+
+int64_t PersistentInteger::Get() {
+  // If not synced, then read.  If the read fails, it's a good idea to write.
+  if (!synced_ && !Read())
+    Write();
+  return value_;
+}
+
+int64_t PersistentInteger::GetAndClear() {
+  int64_t v = Get();
+  Set(0);
+  return v;
+}
+
+void PersistentInteger::Add(int64_t x) {
+  Set(Get() + x);
+}
+
+void PersistentInteger::Write() {
+  int fd = HANDLE_EINTR(open(backing_file_name_.c_str(),
+                             O_WRONLY | O_CREAT | O_TRUNC,
+                             S_IWUSR | S_IRUSR | S_IRGRP | S_IROTH));
+  PCHECK(fd >= 0) << "cannot open " << backing_file_name_ << " for writing";
+  PCHECK((HANDLE_EINTR(write(fd, &version_, sizeof(version_))) ==
+          sizeof(version_)) &&
+         (HANDLE_EINTR(write(fd, &value_, sizeof(value_))) ==
+          sizeof(value_)))
+      << "cannot write to " << backing_file_name_;
+  close(fd);
+  synced_ = true;
+}
+
+bool PersistentInteger::Read() {
+  int fd = HANDLE_EINTR(open(backing_file_name_.c_str(), O_RDONLY));
+  if (fd < 0) {
+    PLOG(WARNING) << "cannot open " << backing_file_name_ << " for reading";
+    return false;
+  }
+  int32_t version;
+  int64_t value;
+  bool read_succeeded = false;
+  if (HANDLE_EINTR(read(fd, &version, sizeof(version))) == sizeof(version) &&
+      version == version_ &&
+      HANDLE_EINTR(read(fd, &value, sizeof(value))) == sizeof(value)) {
+    value_ = value;
+    read_succeeded = true;
+    synced_ = true;
+  }
+  close(fd);
+  return read_succeeded;
+}
+
+void PersistentInteger::SetTestingMode(bool testing) {
+  testing_ = testing;
+}
+
+
+}  // namespace chromeos_metrics
diff --git a/metricsd/persistent_integer.h b/metricsd/persistent_integer.h
new file mode 100644
index 000000000..b1cfcf4ef
--- /dev/null
+++ b/metricsd/persistent_integer.h
@@ -0,0 +1,67 @@
+// Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_PERSISTENT_INTEGER_H_
+#define METRICS_PERSISTENT_INTEGER_H_
+
+#include <stdint.h>
+
+#include <string>
+
+namespace chromeos_metrics {
+
+// PersistentIntegers is a named 64-bit integer value backed by a file.
+// The in-memory value acts as a write-through cache of the file value.
+// If the backing file doesn't exist or has bad content, the value is 0.
+
+class PersistentInteger {
+ public:
+  explicit PersistentInteger(const std::string& name);
+
+  // Virtual only because of mock.
+  virtual ~PersistentInteger();
+
+  // Sets the value.  This writes through to the backing file.
+  void Set(int64_t v);
+
+  // Gets the value.  May sync from backing file first.
+  int64_t Get();
+
+  // Returns the name of the object.
+  std::string Name() { return name_; }
+
+  // Convenience function for Get() followed by Set(0).
+  int64_t GetAndClear();
+
+  // Convenience function for v = Get, Set(v + x).
+  // Virtual only because of mock.
+  virtual void Add(int64_t x);
+
+  // After calling with |testing| = true, changes some behavior for the purpose
+  // of testing.  For instance: instances created while testing use the current
+  // directory for the backing files.
+  static void SetTestingMode(bool testing);
+
+ private:
+  static const int kVersion = 1001;
+
+  // Writes |value_| to the backing file, creating it if necessary.
+  void Write();
+
+  // Reads the value from the backing file, stores it in |value_|, and returns
+  // true if the backing file is valid.  Returns false otherwise, and creates
+  // a valid backing file as a side effect.
+  bool Read();
+
+  int64_t value_;
+  int32_t version_;
+  std::string name_;
+  std::string backing_file_name_;
+  bool synced_;
+  static bool testing_;
+};
+
+}  // namespace chromeos_metrics
+
+#endif  // METRICS_PERSISTENT_INTEGER_H_
diff --git a/metricsd/persistent_integer_mock.h b/metricsd/persistent_integer_mock.h
new file mode 100644
index 000000000..31bfc3515
--- /dev/null
+++ b/metricsd/persistent_integer_mock.h
@@ -0,0 +1,25 @@
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_PERSISTENT_INTEGER_MOCK_H_
+#define METRICS_PERSISTENT_INTEGER_MOCK_H_
+
+#include <string>
+
+#include <gmock/gmock.h>
+
+#include "persistent_integer.h"
+
+namespace chromeos_metrics {
+
+class PersistentIntegerMock : public PersistentInteger {
+ public:
+  explicit PersistentIntegerMock(const std::string& name)
+      : PersistentInteger(name) {}
+    MOCK_METHOD1(Add, void(int64_t count));
+};
+
+}  // namespace chromeos_metrics
+
+#endif  // METRICS_PERSISTENT_INTEGER_MOCK_H_
diff --git a/metricsd/persistent_integer_test.cc b/metricsd/persistent_integer_test.cc
new file mode 100644
index 000000000..4fccb7286
--- /dev/null
+++ b/metricsd/persistent_integer_test.cc
@@ -0,0 +1,66 @@
+// Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <gtest/gtest.h>
+
+#include <base/compiler_specific.h>
+#include <base/files/file_enumerator.h>
+#include <base/files/file_util.h>
+
+#include "persistent_integer.h"
+
+const char kBackingFileName[] = "1.pibakf";
+const char kBackingFilePattern[] = "*.pibakf";
+
+using chromeos_metrics::PersistentInteger;
+
+class PersistentIntegerTest : public testing::Test {
+  void SetUp() override {
+    // Set testing mode.
+    chromeos_metrics::PersistentInteger::SetTestingMode(true);
+  }
+
+  void TearDown() override {
+    // Remove backing files.  The convention is that they all end in ".pibakf".
+    base::FileEnumerator f_enum(base::FilePath("."),
+                                false,
+                                base::FileEnumerator::FILES,
+                                FILE_PATH_LITERAL(kBackingFilePattern));
+    for (base::FilePath name = f_enum.Next();
+         !name.empty();
+         name = f_enum.Next()) {
+      base::DeleteFile(name, false);
+    }
+  }
+};
+
+TEST_F(PersistentIntegerTest, BasicChecks) {
+  scoped_ptr<PersistentInteger> pi(new PersistentInteger(kBackingFileName));
+
+  // Test initialization.
+  EXPECT_EQ(0, pi->Get());
+  EXPECT_EQ(kBackingFileName, pi->Name());  // boring
+
+  // Test set and add.
+  pi->Set(2);
+  pi->Add(3);
+  EXPECT_EQ(5, pi->Get());
+
+  // Test persistence.
+  pi.reset(new PersistentInteger(kBackingFileName));
+  EXPECT_EQ(5, pi->Get());
+
+  // Test GetAndClear.
+  EXPECT_EQ(5, pi->GetAndClear());
+  EXPECT_EQ(pi->Get(), 0);
+
+  // Another persistence test.
+  pi.reset(new PersistentInteger(kBackingFileName));
+  EXPECT_EQ(0, pi->Get());
+}
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
diff --git a/metricsd/platform2_preinstall.sh b/metricsd/platform2_preinstall.sh
new file mode 100755
index 000000000..ccf353ff4
--- /dev/null
+++ b/metricsd/platform2_preinstall.sh
@@ -0,0 +1,13 @@
+#!/bin/bash
+
+# Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+set -e
+
+OUT=$1
+shift
+for v; do
+  sed -e "s/@BSLOT@/${v}/g" libmetrics.pc.in > "${OUT}/lib/libmetrics-${v}.pc"
+done
diff --git a/metricsd/serialization/metric_sample.cc b/metricsd/serialization/metric_sample.cc
new file mode 100644
index 000000000..bc6583d7b
--- /dev/null
+++ b/metricsd/serialization/metric_sample.cc
@@ -0,0 +1,197 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "serialization/metric_sample.h"
+
+#include <string>
+#include <vector>
+
+#include "base/logging.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_split.h"
+#include "base/strings/stringprintf.h"
+
+namespace metrics {
+
+MetricSample::MetricSample(MetricSample::SampleType sample_type,
+                           const std::string& metric_name,
+                           int sample,
+                           int min,
+                           int max,
+                           int bucket_count)
+    : type_(sample_type),
+      name_(metric_name),
+      sample_(sample),
+      min_(min),
+      max_(max),
+      bucket_count_(bucket_count) {
+}
+
+MetricSample::~MetricSample() {
+}
+
+bool MetricSample::IsValid() const {
+  return name().find(' ') == std::string::npos &&
+         name().find('\0') == std::string::npos && !name().empty();
+}
+
+std::string MetricSample::ToString() const {
+  if (type_ == CRASH) {
+    return base::StringPrintf("crash%c%s%c",
+                              '\0',
+                              name().c_str(),
+                              '\0');
+  } else if (type_ == SPARSE_HISTOGRAM) {
+    return base::StringPrintf("sparsehistogram%c%s %d%c",
+                              '\0',
+                              name().c_str(),
+                              sample_,
+                              '\0');
+  } else if (type_ == LINEAR_HISTOGRAM) {
+    return base::StringPrintf("linearhistogram%c%s %d %d%c",
+                              '\0',
+                              name().c_str(),
+                              sample_,
+                              max_,
+                              '\0');
+  } else if (type_ == HISTOGRAM) {
+    return base::StringPrintf("histogram%c%s %d %d %d %d%c",
+                              '\0',
+                              name().c_str(),
+                              sample_,
+                              min_,
+                              max_,
+                              bucket_count_,
+                              '\0');
+  } else {
+    // The type can only be USER_ACTION.
+    CHECK_EQ(type_, USER_ACTION);
+    return base::StringPrintf("useraction%c%s%c",
+                              '\0',
+                              name().c_str(),
+                              '\0');
+  }
+}
+
+int MetricSample::sample() const {
+  CHECK_NE(type_, USER_ACTION);
+  CHECK_NE(type_, CRASH);
+  return sample_;
+}
+
+int MetricSample::min() const {
+  CHECK_EQ(type_, HISTOGRAM);
+  return min_;
+}
+
+int MetricSample::max() const {
+  CHECK_NE(type_, CRASH);
+  CHECK_NE(type_, USER_ACTION);
+  CHECK_NE(type_, SPARSE_HISTOGRAM);
+  return max_;
+}
+
+int MetricSample::bucket_count() const {
+  CHECK_EQ(type_, HISTOGRAM);
+  return bucket_count_;
+}
+
+// static
+scoped_ptr<MetricSample> MetricSample::CrashSample(
+    const std::string& crash_name) {
+  return scoped_ptr<MetricSample>(
+      new MetricSample(CRASH, crash_name, 0, 0, 0, 0));
+}
+
+// static
+scoped_ptr<MetricSample> MetricSample::HistogramSample(
+    const std::string& histogram_name,
+    int sample,
+    int min,
+    int max,
+    int bucket_count) {
+  return scoped_ptr<MetricSample>(new MetricSample(
+      HISTOGRAM, histogram_name, sample, min, max, bucket_count));
+}
+
+// static
+scoped_ptr<MetricSample> MetricSample::ParseHistogram(
+    const std::string& serialized_histogram) {
+  std::vector<std::string> parts;
+  base::SplitString(serialized_histogram, ' ', &parts);
+
+  if (parts.size() != 5)
+    return scoped_ptr<MetricSample>();
+  int sample, min, max, bucket_count;
+  if (parts[0].empty() || !base::StringToInt(parts[1], &sample) ||
+      !base::StringToInt(parts[2], &min) ||
+      !base::StringToInt(parts[3], &max) ||
+      !base::StringToInt(parts[4], &bucket_count)) {
+    return scoped_ptr<MetricSample>();
+  }
+
+  return HistogramSample(parts[0], sample, min, max, bucket_count);
+}
+
+// static
+scoped_ptr<MetricSample> MetricSample::SparseHistogramSample(
+    const std::string& histogram_name,
+    int sample) {
+  return scoped_ptr<MetricSample>(
+      new MetricSample(SPARSE_HISTOGRAM, histogram_name, sample, 0, 0, 0));
+}
+
+// static
+scoped_ptr<MetricSample> MetricSample::ParseSparseHistogram(
+    const std::string& serialized_histogram) {
+  std::vector<std::string> parts;
+  base::SplitString(serialized_histogram, ' ', &parts);
+  if (parts.size() != 2)
+    return scoped_ptr<MetricSample>();
+  int sample;
+  if (parts[0].empty() || !base::StringToInt(parts[1], &sample))
+    return scoped_ptr<MetricSample>();
+
+  return SparseHistogramSample(parts[0], sample);
+}
+
+// static
+scoped_ptr<MetricSample> MetricSample::LinearHistogramSample(
+    const std::string& histogram_name,
+    int sample,
+    int max) {
+  return scoped_ptr<MetricSample>(
+      new MetricSample(LINEAR_HISTOGRAM, histogram_name, sample, 0, max, 0));
+}
+
+// static
+scoped_ptr<MetricSample> MetricSample::ParseLinearHistogram(
+    const std::string& serialized_histogram) {
+  std::vector<std::string> parts;
+  int sample, max;
+  base::SplitString(serialized_histogram, ' ', &parts);
+  if (parts.size() != 3)
+    return scoped_ptr<MetricSample>();
+  if (parts[0].empty() || !base::StringToInt(parts[1], &sample) ||
+      !base::StringToInt(parts[2], &max)) {
+    return scoped_ptr<MetricSample>();
+  }
+
+  return LinearHistogramSample(parts[0], sample, max);
+}
+
+// static
+scoped_ptr<MetricSample> MetricSample::UserActionSample(
+    const std::string& action_name) {
+  return scoped_ptr<MetricSample>(
+      new MetricSample(USER_ACTION, action_name, 0, 0, 0, 0));
+}
+
+bool MetricSample::IsEqual(const MetricSample& metric) {
+  return type_ == metric.type_ && name_ == metric.name_ &&
+         sample_ == metric.sample_ && min_ == metric.min_ &&
+         max_ == metric.max_ && bucket_count_ == metric.bucket_count_;
+}
+
+}  // namespace metrics
diff --git a/metricsd/serialization/metric_sample.h b/metricsd/serialization/metric_sample.h
new file mode 100644
index 000000000..877114d0a
--- /dev/null
+++ b/metricsd/serialization/metric_sample.h
@@ -0,0 +1,119 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_SERIALIZATION_METRIC_SAMPLE_H_
+#define METRICS_SERIALIZATION_METRIC_SAMPLE_H_
+
+#include <string>
+
+#include "base/gtest_prod_util.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+
+namespace metrics {
+
+// This class is used by libmetrics (ChromeOS) to serialize
+// and deserialize measurements to send them to a metrics sending service.
+// It is meant to be a simple container with serialization functions.
+class MetricSample {
+ public:
+  // Types of metric sample used.
+  enum SampleType {
+    CRASH,
+    HISTOGRAM,
+    LINEAR_HISTOGRAM,
+    SPARSE_HISTOGRAM,
+    USER_ACTION
+  };
+
+  ~MetricSample();
+
+  // Returns true if the sample is valid (can be serialized without ambiguity).
+  //
+  // This function should be used to filter bad samples before serializing them.
+  bool IsValid() const;
+
+  // Getters for type and name. All types of metrics have these so we do not
+  // need to check the type.
+  SampleType type() const { return type_; }
+  const std::string& name() const { return name_; }
+
+  // Getters for sample, min, max, bucket_count.
+  // Check the metric type to make sure the request make sense. (ex: a crash
+  // sample does not have a bucket_count so we crash if we call bucket_count()
+  // on it.)
+  int sample() const;
+  int min() const;
+  int max() const;
+  int bucket_count() const;
+
+  // Returns a serialized version of the sample.
+  //
+  // The serialized message for each type is:
+  // crash: crash\0|name_|\0
+  // user action: useraction\0|name_|\0
+  // histogram: histogram\0|name_| |sample_| |min_| |max_| |bucket_count_|\0
+  // sparsehistogram: sparsehistogram\0|name_| |sample_|\0
+  // linearhistogram: linearhistogram\0|name_| |sample_| |max_|\0
+  std::string ToString() const;
+
+  // Builds a crash sample.
+  static scoped_ptr<MetricSample> CrashSample(const std::string& crash_name);
+
+  // Builds a histogram sample.
+  static scoped_ptr<MetricSample> HistogramSample(
+      const std::string& histogram_name,
+      int sample,
+      int min,
+      int max,
+      int bucket_count);
+  // Deserializes a histogram sample.
+  static scoped_ptr<MetricSample> ParseHistogram(const std::string& serialized);
+
+  // Builds a sparse histogram sample.
+  static scoped_ptr<MetricSample> SparseHistogramSample(
+      const std::string& histogram_name,
+      int sample);
+  // Deserializes a sparse histogram sample.
+  static scoped_ptr<MetricSample> ParseSparseHistogram(
+      const std::string& serialized);
+
+  // Builds a linear histogram sample.
+  static scoped_ptr<MetricSample> LinearHistogramSample(
+      const std::string& histogram_name,
+      int sample,
+      int max);
+  // Deserializes a linear histogram sample.
+  static scoped_ptr<MetricSample> ParseLinearHistogram(
+      const std::string& serialized);
+
+  // Builds a user action sample.
+  static scoped_ptr<MetricSample> UserActionSample(
+      const std::string& action_name);
+
+  // Returns true if sample and this object represent the same sample (type,
+  // name, sample, min, max, bucket_count match).
+  bool IsEqual(const MetricSample& sample);
+
+ private:
+  MetricSample(SampleType sample_type,
+               const std::string& metric_name,
+               const int sample,
+               const int min,
+               const int max,
+               const int bucket_count);
+
+  const SampleType type_;
+  const std::string name_;
+  const int sample_;
+  const int min_;
+  const int max_;
+  const int bucket_count_;
+
+  DISALLOW_COPY_AND_ASSIGN(MetricSample);
+};
+
+}  // namespace metrics
+
+#endif  // METRICS_SERIALIZATION_METRIC_SAMPLE_H_
diff --git a/metricsd/serialization/serialization_utils.cc b/metricsd/serialization/serialization_utils.cc
new file mode 100644
index 000000000..d18dcd754
--- /dev/null
+++ b/metricsd/serialization/serialization_utils.cc
@@ -0,0 +1,221 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "serialization/serialization_utils.h"
+
+#include <sys/file.h>
+
+#include <string>
+#include <vector>
+
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/files/scoped_file.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
+#include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
+#include "serialization/metric_sample.h"
+
+#define READ_WRITE_ALL_FILE_FLAGS \
+  (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH)
+
+namespace metrics {
+namespace {
+
+// Reads the next message from |file_descriptor| into |message|.
+//
+// |message| will be set to the empty string if no message could be read (EOF)
+// or the message was badly constructed.
+//
+// Returns false if no message can be read from this file anymore (EOF or
+// unrecoverable error).
+bool ReadMessage(int fd, std::string* message) {
+  CHECK(message);
+
+  int result;
+  int32_t message_size;
+  const int32_t message_hdr_size = sizeof(message_size);
+  // The file containing the metrics do not leave the device so the writer and
+  // the reader will always have the same endianness.
+  result = HANDLE_EINTR(read(fd, &message_size, sizeof(message_size)));
+  if (result < 0) {
+    DPLOG(ERROR) << "reading metrics message header";
+    return false;
+  }
+  if (result == 0) {
+    // This indicates a normal EOF.
+    return false;
+  }
+  if (result < message_hdr_size) {
+    DLOG(ERROR) << "bad read size " << result << ", expecting "
+                << sizeof(message_size);
+    return false;
+  }
+
+  // kMessageMaxLength applies to the entire message: the 4-byte
+  // length field and the content.
+  if (message_size > SerializationUtils::kMessageMaxLength) {
+    DLOG(ERROR) << "message too long : " << message_size;
+    if (HANDLE_EINTR(lseek(fd, message_size - 4, SEEK_CUR)) == -1) {
+      DLOG(ERROR) << "error while skipping message. abort";
+      return false;
+    }
+    // Badly formatted message was skipped. Treat the badly formatted sample as
+    // an empty sample.
+    message->clear();
+    return true;
+  }
+
+  if (message_size < message_hdr_size) {
+    DLOG(ERROR) << "message too short : " << message_size;
+    return false;
+  }
+
+  message_size -= message_hdr_size;  // The message size includes itself.
+  char buffer[SerializationUtils::kMessageMaxLength];
+  if (!base::ReadFromFD(fd, buffer, message_size)) {
+    DPLOG(ERROR) << "reading metrics message body";
+    return false;
+  }
+  *message = std::string(buffer, message_size);
+  return true;
+}
+
+}  // namespace
+
+scoped_ptr<MetricSample> SerializationUtils::ParseSample(
+    const std::string& sample) {
+  if (sample.empty())
+    return scoped_ptr<MetricSample>();
+
+  std::vector<std::string> parts;
+  base::SplitString(sample, '\0', &parts);
+  // We should have two null terminated strings so split should produce
+  // three chunks.
+  if (parts.size() != 3) {
+    DLOG(ERROR) << "splitting message on \\0 produced " << parts.size()
+                << " parts (expected 3)";
+    return scoped_ptr<MetricSample>();
+  }
+  const std::string& name = parts[0];
+  const std::string& value = parts[1];
+
+  if (base::LowerCaseEqualsASCII(name, "crash")) {
+    return MetricSample::CrashSample(value);
+  } else if (base::LowerCaseEqualsASCII(name, "histogram")) {
+    return MetricSample::ParseHistogram(value);
+  } else if (base::LowerCaseEqualsASCII(name, "linearhistogram")) {
+    return MetricSample::ParseLinearHistogram(value);
+  } else if (base::LowerCaseEqualsASCII(name, "sparsehistogram")) {
+    return MetricSample::ParseSparseHistogram(value);
+  } else if (base::LowerCaseEqualsASCII(name, "useraction")) {
+    return MetricSample::UserActionSample(value);
+  } else {
+    DLOG(ERROR) << "invalid event type: " << name << ", value: " << value;
+  }
+  return scoped_ptr<MetricSample>();
+}
+
+void SerializationUtils::ReadAndTruncateMetricsFromFile(
+    const std::string& filename,
+    ScopedVector<MetricSample>* metrics) {
+  struct stat stat_buf;
+  int result;
+
+  result = stat(filename.c_str(), &stat_buf);
+  if (result < 0) {
+    if (errno != ENOENT)
+      DPLOG(ERROR) << filename << ": bad metrics file stat";
+
+    // Nothing to collect---try later.
+    return;
+  }
+  if (stat_buf.st_size == 0) {
+    // Also nothing to collect.
+    return;
+  }
+  base::ScopedFD fd(open(filename.c_str(), O_RDWR));
+  if (fd.get() < 0) {
+    DPLOG(ERROR) << filename << ": cannot open";
+    return;
+  }
+  result = flock(fd.get(), LOCK_EX);
+  if (result < 0) {
+    DPLOG(ERROR) << filename << ": cannot lock";
+    return;
+  }
+
+  // This processes all messages in the log. When all messages are
+  // read and processed, or an error occurs, truncate the file to zero size.
+  for (;;) {
+    std::string message;
+
+    if (!ReadMessage(fd.get(), &message))
+      break;
+
+    scoped_ptr<MetricSample> sample = ParseSample(message);
+    if (sample)
+      metrics->push_back(sample.release());
+  }
+
+  result = ftruncate(fd.get(), 0);
+  if (result < 0)
+    DPLOG(ERROR) << "truncate metrics log";
+
+  result = flock(fd.get(), LOCK_UN);
+  if (result < 0)
+    DPLOG(ERROR) << "unlock metrics log";
+}
+
+bool SerializationUtils::WriteMetricToFile(const MetricSample& sample,
+                                           const std::string& filename) {
+  if (!sample.IsValid())
+    return false;
+
+  base::ScopedFD file_descriptor(open(filename.c_str(),
+                                      O_WRONLY | O_APPEND | O_CREAT,
+                                      READ_WRITE_ALL_FILE_FLAGS));
+
+  if (file_descriptor.get() < 0) {
+    DPLOG(ERROR) << filename << ": cannot open";
+    return false;
+  }
+
+  fchmod(file_descriptor.get(), READ_WRITE_ALL_FILE_FLAGS);
+  // Grab a lock to avoid chrome truncating the file
+  // underneath us. Keep the file locked as briefly as possible.
+  // Freeing file_descriptor will close the file and and remove the lock.
+  if (HANDLE_EINTR(flock(file_descriptor.get(), LOCK_EX)) < 0) {
+    DPLOG(ERROR) << filename << ": cannot lock";
+    return false;
+  }
+
+  std::string msg = sample.ToString();
+  int32 size = msg.length() + sizeof(int32);
+  if (size > kMessageMaxLength) {
+    DLOG(ERROR) << "cannot write message: too long";
+    return false;
+  }
+
+  // The file containing the metrics samples will only be read by programs on
+  // the same device so we do not check endianness.
+  if (!base::WriteFileDescriptor(file_descriptor.get(),
+                                 reinterpret_cast<char*>(&size),
+                                 sizeof(size))) {
+    DPLOG(ERROR) << "error writing message length";
+    return false;
+  }
+
+  if (!base::WriteFileDescriptor(
+          file_descriptor.get(), msg.c_str(), msg.size())) {
+    DPLOG(ERROR) << "error writing message";
+    return false;
+  }
+
+  return true;
+}
+
+}  // namespace metrics
diff --git a/metricsd/serialization/serialization_utils.h b/metricsd/serialization/serialization_utils.h
new file mode 100644
index 000000000..5af61660f
--- /dev/null
+++ b/metricsd/serialization/serialization_utils.h
@@ -0,0 +1,48 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_SERIALIZATION_SERIALIZATION_UTILS_H_
+#define METRICS_SERIALIZATION_SERIALIZATION_UTILS_H_
+
+#include <string>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
+
+namespace metrics {
+
+class MetricSample;
+
+// Metrics helpers to serialize and deserialize metrics collected by
+// ChromeOS.
+namespace SerializationUtils {
+
+// Deserializes a sample passed as a string and return a sample.
+// The return value will either be a scoped_ptr to a Metric sample (if the
+// deserialization was successful) or a NULL scoped_ptr.
+scoped_ptr<MetricSample> ParseSample(const std::string& sample);
+
+// Reads all samples from a file and truncate the file when done.
+void ReadAndTruncateMetricsFromFile(const std::string& filename,
+                                    ScopedVector<MetricSample>* metrics);
+
+// Serializes a sample and write it to filename.
+// The format for the message is:
+//  message_size, serialized_message
+// where
+//  * message_size is the total length of the message (message_size +
+//    serialized_message) on 4 bytes
+//  * serialized_message is the serialized version of sample (using ToString)
+//
+//  NB: the file will never leave the device so message_size will be written
+//  with the architecture's endianness.
+bool WriteMetricToFile(const MetricSample& sample, const std::string& filename);
+
+// Maximum length of a serialized message
+static const int kMessageMaxLength = 1024;
+
+}  // namespace SerializationUtils
+}  // namespace metrics
+
+#endif  // METRICS_SERIALIZATION_SERIALIZATION_UTILS_H_
diff --git a/metricsd/serialization/serialization_utils_unittest.cc b/metricsd/serialization/serialization_utils_unittest.cc
new file mode 100644
index 000000000..fb802bcc9
--- /dev/null
+++ b/metricsd/serialization/serialization_utils_unittest.cc
@@ -0,0 +1,169 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "serialization/serialization_utils.h"
+
+#include <base/files/file_util.h>
+#include <base/files/scoped_temp_dir.h>
+#include <base/logging.h>
+#include <base/strings/stringprintf.h>
+#include <gtest/gtest.h>
+
+#include "serialization/metric_sample.h"
+
+namespace metrics {
+namespace {
+
+class SerializationUtilsTest : public testing::Test {
+ protected:
+  SerializationUtilsTest() {
+    bool success = temporary_dir.CreateUniqueTempDir();
+    if (success) {
+      base::FilePath dir_path = temporary_dir.path();
+      filename = dir_path.value() + "chromeossampletest";
+      filepath = base::FilePath(filename);
+    }
+  }
+
+  void SetUp() override { base::DeleteFile(filepath, false); }
+
+  void TestSerialization(MetricSample* sample) {
+    std::string serialized(sample->ToString());
+    ASSERT_EQ('\0', serialized[serialized.length() - 1]);
+    scoped_ptr<MetricSample> deserialized =
+        SerializationUtils::ParseSample(serialized);
+    ASSERT_TRUE(deserialized);
+    EXPECT_TRUE(sample->IsEqual(*deserialized.get()));
+  }
+
+  std::string filename;
+  base::ScopedTempDir temporary_dir;
+  base::FilePath filepath;
+};
+
+TEST_F(SerializationUtilsTest, CrashSerializeTest) {
+  TestSerialization(MetricSample::CrashSample("test").get());
+}
+
+TEST_F(SerializationUtilsTest, HistogramSerializeTest) {
+  TestSerialization(
+      MetricSample::HistogramSample("myhist", 13, 1, 100, 10).get());
+}
+
+TEST_F(SerializationUtilsTest, LinearSerializeTest) {
+  TestSerialization(
+      MetricSample::LinearHistogramSample("linearhist", 12, 30).get());
+}
+
+TEST_F(SerializationUtilsTest, SparseSerializeTest) {
+  TestSerialization(MetricSample::SparseHistogramSample("mysparse", 30).get());
+}
+
+TEST_F(SerializationUtilsTest, UserActionSerializeTest) {
+  TestSerialization(MetricSample::UserActionSample("myaction").get());
+}
+
+TEST_F(SerializationUtilsTest, IllegalNameAreFilteredTest) {
+  scoped_ptr<MetricSample> sample1 =
+      MetricSample::SparseHistogramSample("no space", 10);
+  scoped_ptr<MetricSample> sample2 = MetricSample::LinearHistogramSample(
+      base::StringPrintf("here%cbhe", '\0'), 1, 3);
+
+  EXPECT_FALSE(SerializationUtils::WriteMetricToFile(*sample1.get(), filename));
+  EXPECT_FALSE(SerializationUtils::WriteMetricToFile(*sample2.get(), filename));
+  int64 size = 0;
+
+  ASSERT_TRUE(!PathExists(filepath) || base::GetFileSize(filepath, &size));
+
+  EXPECT_EQ(0, size);
+}
+
+TEST_F(SerializationUtilsTest, BadInputIsCaughtTest) {
+  std::string input(
+      base::StringPrintf("sparsehistogram%cname foo%c", '\0', '\0'));
+  EXPECT_EQ(NULL, MetricSample::ParseSparseHistogram(input).get());
+}
+
+TEST_F(SerializationUtilsTest, MessageSeparatedByZero) {
+  scoped_ptr<MetricSample> crash = MetricSample::CrashSample("mycrash");
+
+  SerializationUtils::WriteMetricToFile(*crash.get(), filename);
+  int64 size = 0;
+  ASSERT_TRUE(base::GetFileSize(filepath, &size));
+  // 4 bytes for the size
+  // 5 bytes for crash
+  // 7 bytes for mycrash
+  // 2 bytes for the \0
+  // -> total of 18
+  EXPECT_EQ(size, 18);
+}
+
+TEST_F(SerializationUtilsTest, MessagesTooLongAreDiscardedTest) {
+  // Creates a message that is bigger than the maximum allowed size.
+  // As we are adding extra character (crash, \0s, etc), if the name is
+  // kMessageMaxLength long, it will be too long.
+  std::string name(SerializationUtils::kMessageMaxLength, 'c');
+
+  scoped_ptr<MetricSample> crash = MetricSample::CrashSample(name);
+  EXPECT_FALSE(SerializationUtils::WriteMetricToFile(*crash.get(), filename));
+  int64 size = 0;
+  ASSERT_TRUE(base::GetFileSize(filepath, &size));
+  EXPECT_EQ(0, size);
+}
+
+TEST_F(SerializationUtilsTest, ReadLongMessageTest) {
+  base::File test_file(filepath,
+                       base::File::FLAG_OPEN_ALWAYS | base::File::FLAG_APPEND);
+  std::string message(SerializationUtils::kMessageMaxLength + 1, 'c');
+
+  int32 message_size = message.length() + sizeof(int32);
+  test_file.WriteAtCurrentPos(reinterpret_cast<const char*>(&message_size),
+                              sizeof(message_size));
+  test_file.WriteAtCurrentPos(message.c_str(), message.length());
+  test_file.Close();
+
+  scoped_ptr<MetricSample> crash = MetricSample::CrashSample("test");
+  SerializationUtils::WriteMetricToFile(*crash.get(), filename);
+
+  ScopedVector<MetricSample> samples;
+  SerializationUtils::ReadAndTruncateMetricsFromFile(filename, &samples);
+  ASSERT_EQ(size_t(1), samples.size());
+  ASSERT_TRUE(samples[0] != NULL);
+  EXPECT_TRUE(crash->IsEqual(*samples[0]));
+}
+
+TEST_F(SerializationUtilsTest, WriteReadTest) {
+  scoped_ptr<MetricSample> hist =
+      MetricSample::HistogramSample("myhist", 1, 2, 3, 4);
+  scoped_ptr<MetricSample> crash = MetricSample::CrashSample("mycrash");
+  scoped_ptr<MetricSample> lhist =
+      MetricSample::LinearHistogramSample("linear", 1, 10);
+  scoped_ptr<MetricSample> shist =
+      MetricSample::SparseHistogramSample("mysparse", 30);
+  scoped_ptr<MetricSample> action = MetricSample::UserActionSample("myaction");
+
+  SerializationUtils::WriteMetricToFile(*hist.get(), filename);
+  SerializationUtils::WriteMetricToFile(*crash.get(), filename);
+  SerializationUtils::WriteMetricToFile(*lhist.get(), filename);
+  SerializationUtils::WriteMetricToFile(*shist.get(), filename);
+  SerializationUtils::WriteMetricToFile(*action.get(), filename);
+  ScopedVector<MetricSample> vect;
+  SerializationUtils::ReadAndTruncateMetricsFromFile(filename, &vect);
+  ASSERT_EQ(vect.size(), size_t(5));
+  for (int i = 0; i < 5; i++) {
+    ASSERT_TRUE(vect[0] != NULL);
+  }
+  EXPECT_TRUE(hist->IsEqual(*vect[0]));
+  EXPECT_TRUE(crash->IsEqual(*vect[1]));
+  EXPECT_TRUE(lhist->IsEqual(*vect[2]));
+  EXPECT_TRUE(shist->IsEqual(*vect[3]));
+  EXPECT_TRUE(action->IsEqual(*vect[4]));
+
+  int64 size = 0;
+  ASSERT_TRUE(base::GetFileSize(filepath, &size));
+  ASSERT_EQ(0, size);
+}
+
+}  // namespace
+}  // namespace metrics
diff --git a/metricsd/syslog_parser.sh b/metricsd/syslog_parser.sh
new file mode 100755
index 000000000..7d064be96
--- /dev/null
+++ b/metricsd/syslog_parser.sh
@@ -0,0 +1,69 @@
+#! /bin/sh
+
+# This script parses /var/log/syslog for messages from programs that log
+# uptime and disk stats (number of sectors read).  It then outputs
+# these stats in a format usable by the metrics collector, which forwards
+# them to autotest and UMA.
+
+# To add a new metric add a line below, as PROGRAM_NAME  METRIC_NAME.
+# PROGRAM_NAME is the name of the job whose start time we
+# are interested in.  METRIC_NAME is the prefix we want to use for
+# reporting to UMA and autotest.  The script prepends "Time" and
+# "Sectors" to METRIC_NAME for the two available measurements, uptime
+# and number of sectors read thus far.
+
+# You will need to emit messages similar to the following in order to add a
+# a metric using this process.  You will need to emit both a start and stop
+# time and the metric reported will be the difference in values
+
+# Nov 15 08:05 localhost PROGRAM_NAME[822]: start METRIC_NAME time 12 sectors 56
+# Nov 15 08:05 localhost PROGRAM_NAME[822]: stop METRIC_NAME time 24 sectors 68
+
+# If you add metrics without a start, it is assumed you are requesting the
+# time differece from system start
+
+# Metrics we are interested in measuring
+METRICS="
+upstart start_x
+"
+
+first=1
+program=""
+
+# Get the metrics for all things
+for m in $METRICS
+do
+  if [ $first -eq 1 ]
+  then
+    first=0
+    program_name=$m
+  else
+    first=1
+    metrics_name=$m
+
+    # Example of line from /var/log/messages:
+    # Nov 15 08:05:42 localhost connmand[822]: start metric time 12 sectors 56
+    # "upstart:" is $5, 1234 is $9, etc.
+    program="${program}/$program_name([[0-9]+]:|:) start $metrics_name/\
+    {
+      metrics_start[\"${metrics_name}Time\"] = \$9;
+      metrics_start[\"${metrics_name}Sectors\"] = \$11;
+    }"
+    program="${program}/$program_name([[0-9]+]:|:) stop $metrics_name/\
+    {
+        metrics_stop[\"${metrics_name}Time\"] = \$9;
+        metrics_stop[\"${metrics_name}Sectors\"] = \$11;
+    }"
+  fi
+done
+
+# Do all the differencing here
+program="${program}\
+END{
+  for (i in metrics_stop) {
+    value_time = metrics_stop[i] - metrics_start[i];
+    print i \"=\" value_time;
+  }
+}"
+
+exec awk "$program" /var/log/syslog
diff --git a/metricsd/timer.cc b/metricsd/timer.cc
new file mode 100644
index 000000000..ce4bf67a3
--- /dev/null
+++ b/metricsd/timer.cc
@@ -0,0 +1,108 @@
+// Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "timer.h"
+
+#include <string>
+
+#include <base/memory/scoped_ptr.h>
+
+#include "metrics/metrics_library.h"
+
+namespace chromeos_metrics {
+
+base::TimeTicks ClockWrapper::GetCurrentTime() const {
+  return base::TimeTicks::Now();
+}
+
+Timer::Timer()
+    : timer_state_(kTimerStopped),
+      clock_wrapper_(new ClockWrapper()) {}
+
+bool Timer::Start() {
+  elapsed_time_ = base::TimeDelta();  // Sets elapsed_time_ to zero.
+  start_time_ = clock_wrapper_->GetCurrentTime();
+  timer_state_ = kTimerRunning;
+  return true;
+}
+
+bool Timer::Stop() {
+  if (timer_state_ == kTimerStopped)
+    return false;
+  if (timer_state_ == kTimerRunning)
+    elapsed_time_ += clock_wrapper_->GetCurrentTime() - start_time_;
+  timer_state_ = kTimerStopped;
+  return true;
+}
+
+bool Timer::Pause() {
+  switch (timer_state_) {
+    case kTimerStopped:
+      if (!Start())
+        return false;
+      timer_state_ = kTimerPaused;
+      return true;
+    case kTimerRunning:
+      timer_state_ = kTimerPaused;
+      elapsed_time_ += clock_wrapper_->GetCurrentTime() - start_time_;
+      return true;
+    default:
+      return false;
+  }
+}
+
+bool Timer::Resume() {
+  switch (timer_state_) {
+    case kTimerStopped:
+      return Start();
+    case kTimerPaused:
+      start_time_ = clock_wrapper_->GetCurrentTime();
+      timer_state_ = kTimerRunning;
+      return true;
+    default:
+      return false;
+  }
+}
+
+bool Timer::Reset() {
+  elapsed_time_ = base::TimeDelta();  // Sets elapsed_time_ to zero.
+  timer_state_ = kTimerStopped;
+  return true;
+}
+
+bool Timer::HasStarted() const {
+  return timer_state_ != kTimerStopped;
+}
+
+bool Timer::GetElapsedTime(base::TimeDelta* elapsed_time) const {
+  if (start_time_.is_null() || !elapsed_time)
+    return false;
+  *elapsed_time = elapsed_time_;
+  if (timer_state_ == kTimerRunning) {
+    *elapsed_time += clock_wrapper_->GetCurrentTime() - start_time_;
+  }
+  return true;
+}
+
+// static
+MetricsLibraryInterface* TimerReporter::metrics_lib_ = nullptr;
+
+TimerReporter::TimerReporter(const std::string& histogram_name, int min,
+                             int max, int num_buckets)
+    : histogram_name_(histogram_name),
+      min_(min),
+      max_(max),
+      num_buckets_(num_buckets) {}
+
+bool TimerReporter::ReportMilliseconds() const {
+  base::TimeDelta elapsed_time;
+  if (!metrics_lib_ || !GetElapsedTime(&elapsed_time)) return false;
+  return metrics_lib_->SendToUMA(histogram_name_,
+                                 elapsed_time.InMilliseconds(),
+                                 min_,
+                                 max_,
+                                 num_buckets_);
+}
+
+}  // namespace chromeos_metrics
diff --git a/metricsd/timer.h b/metricsd/timer.h
new file mode 100644
index 000000000..52cc57892
--- /dev/null
+++ b/metricsd/timer.h
@@ -0,0 +1,158 @@
+// Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Timer - class that provides timer tracking.
+
+#ifndef METRICS_TIMER_H_
+#define METRICS_TIMER_H_
+
+#include <string>
+
+#include <base/macros.h>
+#include <base/memory/scoped_ptr.h>
+#include <base/time/time.h>
+#include <gtest/gtest_prod.h>  // for FRIEND_TEST
+
+class MetricsLibraryInterface;
+
+namespace chromeos_metrics {
+
+class TimerInterface {
+ public:
+  virtual ~TimerInterface() {}
+
+  virtual bool Start() = 0;
+  virtual bool Stop() = 0;
+  virtual bool Reset() = 0;
+  virtual bool HasStarted() const = 0;
+};
+
+// Wrapper for calls to the system clock.
+class ClockWrapper {
+ public:
+  ClockWrapper() {}
+  virtual ~ClockWrapper() {}
+
+  // Returns the current time from the system.
+  virtual base::TimeTicks GetCurrentTime() const;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ClockWrapper);
+};
+
+// Implements a Timer.
+class Timer : public TimerInterface {
+ public:
+  Timer();
+  virtual ~Timer() {}
+
+  // Starts the timer. If a timer is already running, also resets current
+  // timer. Always returns true.
+  virtual bool Start();
+
+  // Stops the timer and calculates the total time elapsed between now and when
+  // Start() was called. Note that this method needs a prior call to Start().
+  // Otherwise, it fails (returns false).
+  virtual bool Stop();
+
+  // Pauses a timer.  If the timer is stopped, this call starts the timer in
+  // the paused state. Fails (returns false) if the timer is already paused.
+  virtual bool Pause();
+
+  // Restarts a paused timer (or starts a stopped timer). This method fails
+  // (returns false) if the timer is already running; otherwise, returns true.
+  virtual bool Resume();
+
+  // Resets the timer, erasing the current duration being tracked. Always
+  // returns true.
+  virtual bool Reset();
+
+  // Returns whether the timer has started or not.
+  virtual bool HasStarted() const;
+
+  // Stores the current elapsed time in |elapsed_time|. If timer is stopped,
+  // stores the elapsed time from when Stop() was last called. Otherwise,
+  // calculates and stores the elapsed time since the last Start().
+  // Returns false if the timer was never Start()'ed or if called with a null
+  // pointer argument.
+  virtual bool GetElapsedTime(base::TimeDelta* elapsed_time) const;
+
+ private:
+  enum TimerState { kTimerStopped, kTimerRunning, kTimerPaused };
+  friend class TimerTest;
+  friend class TimerReporterTest;
+  FRIEND_TEST(TimerReporterTest, StartStopReport);
+  FRIEND_TEST(TimerTest, InvalidElapsedTime);
+  FRIEND_TEST(TimerTest, InvalidStop);
+  FRIEND_TEST(TimerTest, PauseResumeStop);
+  FRIEND_TEST(TimerTest, PauseStartStopResume);
+  FRIEND_TEST(TimerTest, PauseStop);
+  FRIEND_TEST(TimerTest, Reset);
+  FRIEND_TEST(TimerTest, ReStart);
+  FRIEND_TEST(TimerTest, ResumeStartStopPause);
+  FRIEND_TEST(TimerTest, SeparatedTimers);
+  FRIEND_TEST(TimerTest, StartPauseResumePauseResumeStop);
+  FRIEND_TEST(TimerTest, StartPauseResumePauseStop);
+  FRIEND_TEST(TimerTest, StartPauseResumeStop);
+  FRIEND_TEST(TimerTest, StartPauseStop);
+  FRIEND_TEST(TimerTest, StartResumeStop);
+  FRIEND_TEST(TimerTest, StartStop);
+
+  // Elapsed time of the last use of the timer.
+  base::TimeDelta elapsed_time_;
+
+  // Starting time value.
+  base::TimeTicks start_time_;
+
+  // Whether the timer is running, stopped, or paused.
+  TimerState timer_state_;
+
+  // Wrapper for the calls to the system clock.
+  scoped_ptr<ClockWrapper> clock_wrapper_;
+
+  DISALLOW_COPY_AND_ASSIGN(Timer);
+};
+
+// Extends the Timer class to report the elapsed time in milliseconds through
+// the UMA metrics library.
+class TimerReporter : public Timer {
+ public:
+  // Initializes the timer by providing a |histogram_name| to report to with
+  // |min|, |max| and |num_buckets| attributes for the histogram.
+  TimerReporter(const std::string& histogram_name, int min, int max,
+                int num_buckets);
+  virtual ~TimerReporter() {}
+
+  // Sets the metrics library used by all instances of this class.
+  static void set_metrics_lib(MetricsLibraryInterface* metrics_lib) {
+    metrics_lib_ = metrics_lib;
+  }
+
+  // Reports the current duration to UMA, in milliseconds. Returns false if
+  // there is nothing to report, e.g. a metrics library is not set.
+  virtual bool ReportMilliseconds() const;
+
+  // Accessor methods.
+  const std::string& histogram_name() const { return histogram_name_; }
+  int min() const { return min_; }
+  int max() const { return max_; }
+  int num_buckets() const { return num_buckets_; }
+
+ private:
+  friend class TimerReporterTest;
+  FRIEND_TEST(TimerReporterTest, StartStopReport);
+  FRIEND_TEST(TimerReporterTest, InvalidReport);
+
+  static MetricsLibraryInterface* metrics_lib_;
+  std::string histogram_name_;
+  int min_;
+  int max_;
+  int num_buckets_;
+
+  DISALLOW_COPY_AND_ASSIGN(TimerReporter);
+};
+
+}  // namespace chromeos_metrics
+
+#endif  // METRICS_TIMER_H_
diff --git a/metricsd/timer_mock.h b/metricsd/timer_mock.h
new file mode 100644
index 000000000..ed76f12cd
--- /dev/null
+++ b/metricsd/timer_mock.h
@@ -0,0 +1,47 @@
+// Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_TIMER_MOCK_H_
+#define METRICS_TIMER_MOCK_H_
+
+#include <string>
+
+#include <gmock/gmock.h>
+
+#include "timer.h"
+
+namespace chromeos_metrics {
+
+class TimerMock : public Timer {
+ public:
+  MOCK_METHOD0(Start, bool());
+  MOCK_METHOD0(Stop, bool());
+  MOCK_METHOD0(Reset, bool());
+  MOCK_CONST_METHOD0(HasStarted, bool());
+  MOCK_CONST_METHOD1(GetElapsedTime, bool(base::TimeDelta* elapsed_time));
+};
+
+class TimerReporterMock : public TimerReporter {
+ public:
+  TimerReporterMock() : TimerReporter("", 0, 0, 0) {}
+  MOCK_METHOD0(Start, bool());
+  MOCK_METHOD0(Stop, bool());
+  MOCK_METHOD0(Reset, bool());
+  MOCK_CONST_METHOD0(HasStarted, bool());
+  MOCK_CONST_METHOD1(GetElapsedTime, bool(base::TimeDelta* elapsed_time));
+  MOCK_CONST_METHOD0(ReportMilliseconds, bool());
+  MOCK_CONST_METHOD0(histogram_name, std::string&());
+  MOCK_CONST_METHOD0(min, int());
+  MOCK_CONST_METHOD0(max, int());
+  MOCK_CONST_METHOD0(num_buckets, int());
+};
+
+class ClockWrapperMock : public ClockWrapper {
+ public:
+  MOCK_CONST_METHOD0(GetCurrentTime, base::TimeTicks());
+};
+
+}  // namespace chromeos_metrics
+
+#endif  // METRICS_TIMER_MOCK_H_
diff --git a/metricsd/timer_test.cc b/metricsd/timer_test.cc
new file mode 100644
index 000000000..b1689bf8c
--- /dev/null
+++ b/metricsd/timer_test.cc
@@ -0,0 +1,452 @@
+// Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stdint.h>
+
+#include <base/memory/scoped_ptr.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+#include "metrics_library_mock.h"
+#include "timer.h"
+#include "timer_mock.h"
+
+using ::testing::_;
+using ::testing::Return;
+
+namespace chromeos_metrics {
+
+namespace {
+const int64_t kStime1MSec = 1400;
+const int64_t kEtime1MSec = 3000;
+const int64_t kDelta1MSec = 1600;
+
+const int64_t kStime2MSec = 4200;
+const int64_t kEtime2MSec = 5000;
+const int64_t kDelta2MSec = 800;
+
+const int64_t kStime3MSec = 6600;
+const int64_t kEtime3MSec = 6800;
+const int64_t kDelta3MSec = 200;
+}  // namespace
+
+class TimerTest : public testing::Test {
+ public:
+  TimerTest() : clock_wrapper_mock_(new ClockWrapperMock()) {}
+
+ protected:
+  virtual void SetUp() {
+    EXPECT_EQ(Timer::kTimerStopped, timer_.timer_state_);
+    stime += base::TimeDelta::FromMilliseconds(kStime1MSec);
+    etime += base::TimeDelta::FromMilliseconds(kEtime1MSec);
+    stime2 += base::TimeDelta::FromMilliseconds(kStime2MSec);
+    etime2 += base::TimeDelta::FromMilliseconds(kEtime2MSec);
+    stime3 += base::TimeDelta::FromMilliseconds(kStime3MSec);
+    etime3 += base::TimeDelta::FromMilliseconds(kEtime3MSec);
+  }
+
+  virtual void TearDown() {}
+
+  Timer timer_;
+  scoped_ptr<ClockWrapperMock> clock_wrapper_mock_;
+  base::TimeTicks stime, etime, stime2, etime2, stime3, etime3;
+};
+
+TEST_F(TimerTest, StartStop) {
+  EXPECT_CALL(*clock_wrapper_mock_, GetCurrentTime())
+      .WillOnce(Return(stime))
+      .WillOnce(Return(etime));
+  timer_.clock_wrapper_.reset(clock_wrapper_mock_.release());
+  ASSERT_TRUE(timer_.Start());
+  ASSERT_TRUE(timer_.start_time_ == stime);
+  ASSERT_TRUE(timer_.HasStarted());
+  ASSERT_TRUE(timer_.Stop());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), kDelta1MSec);
+
+  base::TimeDelta elapsed_time;
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+
+  ASSERT_FALSE(timer_.HasStarted());
+}
+
+TEST_F(TimerTest, ReStart) {
+  EXPECT_CALL(*clock_wrapper_mock_, GetCurrentTime())
+      .WillOnce(Return(stime))
+      .WillOnce(Return(etime));
+  timer_.clock_wrapper_.reset(clock_wrapper_mock_.release());
+  timer_.Start();
+  base::TimeTicks buffer = timer_.start_time_;
+  timer_.Start();
+  ASSERT_FALSE(timer_.start_time_ == buffer);
+}
+
+TEST_F(TimerTest, Reset) {
+  EXPECT_CALL(*clock_wrapper_mock_, GetCurrentTime())
+      .WillOnce(Return(stime));
+  timer_.clock_wrapper_.reset(clock_wrapper_mock_.release());
+  timer_.Start();
+  ASSERT_TRUE(timer_.Reset());
+  ASSERT_FALSE(timer_.HasStarted());
+}
+
+TEST_F(TimerTest, SeparatedTimers) {
+  EXPECT_CALL(*clock_wrapper_mock_, GetCurrentTime())
+      .WillOnce(Return(stime))
+      .WillOnce(Return(etime))
+      .WillOnce(Return(stime2))
+      .WillOnce(Return(etime2));
+  timer_.clock_wrapper_.reset(clock_wrapper_mock_.release());
+  ASSERT_TRUE(timer_.Start());
+  ASSERT_TRUE(timer_.Stop());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), kDelta1MSec);
+  ASSERT_TRUE(timer_.Start());
+  ASSERT_TRUE(timer_.start_time_ == stime2);
+  ASSERT_TRUE(timer_.Stop());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), kDelta2MSec);
+  ASSERT_FALSE(timer_.HasStarted());
+
+  base::TimeDelta elapsed_time;
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+}
+
+TEST_F(TimerTest, InvalidStop) {
+  EXPECT_CALL(*clock_wrapper_mock_, GetCurrentTime())
+      .WillOnce(Return(stime))
+      .WillOnce(Return(etime));
+  timer_.clock_wrapper_.reset(clock_wrapper_mock_.release());
+  ASSERT_FALSE(timer_.Stop());
+  // Now we try it again, but after a valid start/stop.
+  timer_.Start();
+  timer_.Stop();
+  base::TimeDelta elapsed_time = timer_.elapsed_time_;
+  ASSERT_FALSE(timer_.Stop());
+  ASSERT_TRUE(elapsed_time == timer_.elapsed_time_);
+}
+
+TEST_F(TimerTest, InvalidElapsedTime) {
+  base::TimeDelta elapsed_time;
+  ASSERT_FALSE(timer_.GetElapsedTime(&elapsed_time));
+}
+
+TEST_F(TimerTest, PauseStartStopResume) {
+  EXPECT_CALL(*clock_wrapper_mock_, GetCurrentTime())
+      .WillOnce(Return(stime))
+      .WillOnce(Return(stime2))
+      .WillOnce(Return(etime2))
+      .WillOnce(Return(stime3))
+      .WillOnce(Return(etime3));
+  timer_.clock_wrapper_.reset(clock_wrapper_mock_.release());
+  ASSERT_TRUE(timer_.Pause());  // Starts timer paused.
+  ASSERT_TRUE(timer_.start_time_ == stime);
+  ASSERT_TRUE(timer_.HasStarted());
+
+  ASSERT_TRUE(timer_.Start());  // Restarts timer.
+  ASSERT_TRUE(timer_.start_time_ == stime2);
+  ASSERT_TRUE(timer_.HasStarted());
+
+  ASSERT_TRUE(timer_.Stop());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), kDelta2MSec);
+  ASSERT_FALSE(timer_.HasStarted());
+  base::TimeDelta elapsed_time;
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+
+  ASSERT_TRUE(timer_.Resume());
+  ASSERT_TRUE(timer_.HasStarted());
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(kDelta3MSec, elapsed_time.InMilliseconds());
+}
+
+TEST_F(TimerTest, ResumeStartStopPause) {
+  EXPECT_CALL(*clock_wrapper_mock_, GetCurrentTime())
+      .WillOnce(Return(stime))
+      .WillOnce(Return(stime2))
+      .WillOnce(Return(etime2))
+      .WillOnce(Return(stime3));
+  timer_.clock_wrapper_.reset(clock_wrapper_mock_.release());
+  ASSERT_TRUE(timer_.Resume());
+  ASSERT_TRUE(timer_.start_time_ == stime);
+  ASSERT_TRUE(timer_.HasStarted());
+
+  ASSERT_TRUE(timer_.Start());
+  ASSERT_TRUE(timer_.start_time_ == stime2);
+  ASSERT_TRUE(timer_.HasStarted());
+
+  ASSERT_TRUE(timer_.Stop());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), kDelta2MSec);
+  ASSERT_FALSE(timer_.HasStarted());
+  base::TimeDelta elapsed_time;
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+
+  ASSERT_TRUE(timer_.Pause());
+  ASSERT_TRUE(timer_.HasStarted());
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(0, elapsed_time.InMilliseconds());
+}
+
+TEST_F(TimerTest, StartResumeStop) {
+  EXPECT_CALL(*clock_wrapper_mock_, GetCurrentTime())
+      .WillOnce(Return(stime))
+      .WillOnce(Return(etime));
+  timer_.clock_wrapper_.reset(clock_wrapper_mock_.release());
+  ASSERT_TRUE(timer_.Start());
+  ASSERT_TRUE(timer_.start_time_ == stime);
+  ASSERT_TRUE(timer_.HasStarted());
+
+  ASSERT_FALSE(timer_.Resume());
+  ASSERT_TRUE(timer_.start_time_ == stime);
+  ASSERT_TRUE(timer_.HasStarted());
+
+  ASSERT_TRUE(timer_.Stop());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), kDelta1MSec);
+  ASSERT_FALSE(timer_.HasStarted());
+  base::TimeDelta elapsed_time;
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+}
+
+TEST_F(TimerTest, StartPauseStop) {
+  EXPECT_CALL(*clock_wrapper_mock_, GetCurrentTime())
+      .WillOnce(Return(stime))
+      .WillOnce(Return(etime));
+  timer_.clock_wrapper_.reset(clock_wrapper_mock_.release());
+  ASSERT_TRUE(timer_.Start());
+  ASSERT_TRUE(timer_.start_time_ == stime);
+  ASSERT_TRUE(timer_.HasStarted());
+
+  ASSERT_TRUE(timer_.Pause());
+  ASSERT_TRUE(timer_.HasStarted());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), kDelta1MSec);
+  base::TimeDelta elapsed_time;
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+
+  ASSERT_TRUE(timer_.Stop());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), kDelta1MSec);
+  ASSERT_FALSE(timer_.HasStarted());
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+}
+
+TEST_F(TimerTest, StartPauseResumeStop) {
+  EXPECT_CALL(*clock_wrapper_mock_, GetCurrentTime())
+      .WillOnce(Return(stime))
+      .WillOnce(Return(etime))
+      .WillOnce(Return(stime2))
+      .WillOnce(Return(etime2));
+  timer_.clock_wrapper_.reset(clock_wrapper_mock_.release());
+  ASSERT_TRUE(timer_.Start());
+  ASSERT_TRUE(timer_.start_time_ == stime);
+  ASSERT_TRUE(timer_.HasStarted());
+
+  ASSERT_TRUE(timer_.Pause());
+  ASSERT_TRUE(timer_.HasStarted());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), kDelta1MSec);
+  base::TimeDelta elapsed_time;
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+
+  ASSERT_TRUE(timer_.Resume());
+  ASSERT_TRUE(timer_.HasStarted());
+
+  ASSERT_TRUE(timer_.Stop());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), kDelta1MSec + kDelta2MSec);
+  ASSERT_FALSE(timer_.HasStarted());
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+}
+
+TEST_F(TimerTest, PauseStop) {
+  EXPECT_CALL(*clock_wrapper_mock_, GetCurrentTime())
+      .WillOnce(Return(stime));
+  timer_.clock_wrapper_.reset(clock_wrapper_mock_.release());
+  ASSERT_TRUE(timer_.Pause());
+  ASSERT_TRUE(timer_.start_time_ == stime);
+  ASSERT_TRUE(timer_.HasStarted());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), 0);
+
+  ASSERT_TRUE(timer_.Stop());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), 0);
+  ASSERT_FALSE(timer_.HasStarted());
+  base::TimeDelta elapsed_time;
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+}
+
+TEST_F(TimerTest, PauseResumeStop) {
+  EXPECT_CALL(*clock_wrapper_mock_, GetCurrentTime())
+      .WillOnce(Return(stime))
+      .WillOnce(Return(stime2))
+      .WillOnce(Return(etime2));
+  timer_.clock_wrapper_.reset(clock_wrapper_mock_.release());
+  ASSERT_TRUE(timer_.Pause());
+  ASSERT_TRUE(timer_.start_time_ == stime);
+  ASSERT_TRUE(timer_.HasStarted());
+
+  ASSERT_TRUE(timer_.Resume());
+  ASSERT_TRUE(timer_.HasStarted());
+
+  ASSERT_TRUE(timer_.Stop());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), kDelta2MSec);
+  ASSERT_FALSE(timer_.HasStarted());
+  base::TimeDelta elapsed_time;
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+}
+
+TEST_F(TimerTest, StartPauseResumePauseStop) {
+  EXPECT_CALL(*clock_wrapper_mock_, GetCurrentTime())
+      .WillOnce(Return(stime))
+      .WillOnce(Return(etime))
+      .WillOnce(Return(stime2))
+      .WillOnce(Return(stime3))
+      .WillOnce(Return(etime3));
+  timer_.clock_wrapper_.reset(clock_wrapper_mock_.release());
+  ASSERT_TRUE(timer_.Start());
+  ASSERT_TRUE(timer_.start_time_ == stime);
+  ASSERT_TRUE(timer_.HasStarted());
+
+  ASSERT_TRUE(timer_.Pause());
+  ASSERT_TRUE(timer_.HasStarted());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), kDelta1MSec);
+  base::TimeDelta elapsed_time;
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+
+  ASSERT_TRUE(timer_.Resume());
+  ASSERT_TRUE(timer_.HasStarted());
+  // Make sure GetElapsedTime works while we're running.
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(kDelta1MSec + kStime3MSec - kStime2MSec,
+            elapsed_time.InMilliseconds());
+
+  ASSERT_TRUE(timer_.Pause());
+  ASSERT_TRUE(timer_.HasStarted());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            kDelta1MSec + kEtime3MSec - kStime2MSec);
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+
+  ASSERT_TRUE(timer_.Stop());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            kDelta1MSec + kEtime3MSec - kStime2MSec);
+  ASSERT_FALSE(timer_.HasStarted());
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+}
+
+TEST_F(TimerTest, StartPauseResumePauseResumeStop) {
+  EXPECT_CALL(*clock_wrapper_mock_, GetCurrentTime())
+      .WillOnce(Return(stime))
+      .WillOnce(Return(etime))
+      .WillOnce(Return(stime2))
+      .WillOnce(Return(etime2))
+      .WillOnce(Return(stime3))
+      .WillOnce(Return(etime3));
+  timer_.clock_wrapper_.reset(clock_wrapper_mock_.release());
+  ASSERT_TRUE(timer_.Start());
+  ASSERT_TRUE(timer_.start_time_ == stime);
+  ASSERT_TRUE(timer_.HasStarted());
+
+  ASSERT_TRUE(timer_.Pause());
+  ASSERT_TRUE(timer_.HasStarted());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), kDelta1MSec);
+  base::TimeDelta elapsed_time;
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+
+  ASSERT_TRUE(timer_.Resume());
+  ASSERT_TRUE(timer_.HasStarted());
+
+  ASSERT_TRUE(timer_.Pause());
+  ASSERT_TRUE(timer_.HasStarted());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(), kDelta1MSec + kDelta2MSec);
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+
+  ASSERT_TRUE(timer_.Resume());
+  ASSERT_TRUE(timer_.HasStarted());
+
+  ASSERT_TRUE(timer_.Stop());
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            kDelta1MSec + kDelta2MSec + kDelta3MSec);
+  ASSERT_FALSE(timer_.HasStarted());
+  ASSERT_TRUE(timer_.GetElapsedTime(&elapsed_time));
+  ASSERT_EQ(timer_.elapsed_time_.InMilliseconds(),
+            elapsed_time.InMilliseconds());
+}
+
+static const char kMetricName[] = "test-timer";
+static const int kMinSample = 0;
+static const int kMaxSample = 120 * 1E6;
+static const int kNumBuckets = 50;
+
+class TimerReporterTest : public testing::Test {
+ public:
+  TimerReporterTest() : timer_reporter_(kMetricName, kMinSample, kMaxSample,
+                                        kNumBuckets),
+                        clock_wrapper_mock_(new ClockWrapperMock()) {}
+
+ protected:
+  virtual void SetUp() {
+    timer_reporter_.set_metrics_lib(&lib_);
+    EXPECT_EQ(timer_reporter_.histogram_name_, kMetricName);
+    EXPECT_EQ(timer_reporter_.min_, kMinSample);
+    EXPECT_EQ(timer_reporter_.max_, kMaxSample);
+    EXPECT_EQ(timer_reporter_.num_buckets_, kNumBuckets);
+    stime += base::TimeDelta::FromMilliseconds(kStime1MSec);
+    etime += base::TimeDelta::FromMilliseconds(kEtime1MSec);
+  }
+
+  virtual void TearDown() {
+    timer_reporter_.set_metrics_lib(nullptr);
+  }
+
+  TimerReporter timer_reporter_;
+  MetricsLibraryMock lib_;
+  scoped_ptr<ClockWrapperMock> clock_wrapper_mock_;
+  base::TimeTicks stime, etime;
+};
+
+TEST_F(TimerReporterTest, StartStopReport) {
+  EXPECT_CALL(*clock_wrapper_mock_, GetCurrentTime())
+      .WillOnce(Return(stime))
+      .WillOnce(Return(etime));
+  timer_reporter_.clock_wrapper_.reset(clock_wrapper_mock_.release());
+  EXPECT_CALL(lib_, SendToUMA(kMetricName, kDelta1MSec, kMinSample, kMaxSample,
+                              kNumBuckets)).WillOnce(Return(true));
+  ASSERT_TRUE(timer_reporter_.Start());
+  ASSERT_TRUE(timer_reporter_.Stop());
+  ASSERT_TRUE(timer_reporter_.ReportMilliseconds());
+}
+
+TEST_F(TimerReporterTest, InvalidReport) {
+  ASSERT_FALSE(timer_reporter_.ReportMilliseconds());
+}
+
+}  // namespace chromeos_metrics
+
+int main(int argc, char **argv) {
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
diff --git a/metricsd/uploader/metrics_hashes.cc b/metricsd/uploader/metrics_hashes.cc
new file mode 100644
index 000000000..f9d0cfeaa
--- /dev/null
+++ b/metricsd/uploader/metrics_hashes.cc
@@ -0,0 +1,39 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "uploader/metrics_hashes.h"
+
+#include "base/logging.h"
+#include "base/md5.h"
+#include "base/sys_byteorder.h"
+
+namespace metrics {
+
+namespace {
+
+// Converts the 8-byte prefix of an MD5 hash into a uint64 value.
+inline uint64_t HashToUInt64(const std::string& hash) {
+  uint64_t value;
+  DCHECK_GE(hash.size(), sizeof(value));
+  memcpy(&value, hash.data(), sizeof(value));
+  return base::HostToNet64(value);
+}
+
+}  // namespace
+
+uint64_t HashMetricName(const std::string& name) {
+  // Create an MD5 hash of the given |name|, represented as a byte buffer
+  // encoded as an std::string.
+  base::MD5Context context;
+  base::MD5Init(&context);
+  base::MD5Update(&context, name);
+
+  base::MD5Digest digest;
+  base::MD5Final(&digest, &context);
+
+  std::string hash_str(reinterpret_cast<char*>(digest.a), arraysize(digest.a));
+  return HashToUInt64(hash_str);
+}
+
+}  // namespace metrics
diff --git a/metricsd/uploader/metrics_hashes.h b/metricsd/uploader/metrics_hashes.h
new file mode 100644
index 000000000..8679077e1
--- /dev/null
+++ b/metricsd/uploader/metrics_hashes.h
@@ -0,0 +1,18 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_UPLOADER_METRICS_HASHES_H_
+#define METRICS_UPLOADER_METRICS_HASHES_H_
+
+#include <string>
+
+namespace metrics {
+
+// Computes a uint64 hash of a given string based on its MD5 hash. Suitable for
+// metric names.
+uint64_t HashMetricName(const std::string& name);
+
+}  // namespace metrics
+
+#endif  // METRICS_UPLOADER_METRICS_HASHES_H_
diff --git a/metricsd/uploader/metrics_hashes_unittest.cc b/metricsd/uploader/metrics_hashes_unittest.cc
new file mode 100644
index 000000000..8cdc7a92d
--- /dev/null
+++ b/metricsd/uploader/metrics_hashes_unittest.cc
@@ -0,0 +1,32 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "uploader/metrics_hashes.h"
+
+#include <base/format_macros.h>
+#include <base/macros.h>
+#include <base/strings/stringprintf.h>
+#include <gtest/gtest.h>
+
+namespace metrics {
+
+// Make sure our ID hashes are the same as what we see on the server side.
+TEST(MetricsUtilTest, HashMetricName) {
+  static const struct {
+    std::string input;
+    std::string output;
+  } cases[] = {
+    {"Back", "0x0557fa923dcee4d0"},
+    {"Forward", "0x67d2f6740a8eaebf"},
+    {"NewTab", "0x290eb683f96572f1"},
+  };
+
+  for (size_t i = 0; i < arraysize(cases); ++i) {
+    uint64_t hash = HashMetricName(cases[i].input);
+    std::string hash_hex = base::StringPrintf("0x%016" PRIx64, hash);
+    EXPECT_EQ(cases[i].output, hash_hex);
+  }
+}
+
+}  // namespace metrics
diff --git a/metricsd/uploader/metrics_log.cc b/metricsd/uploader/metrics_log.cc
new file mode 100644
index 000000000..6f11f8aac
--- /dev/null
+++ b/metricsd/uploader/metrics_log.cc
@@ -0,0 +1,41 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "uploader/metrics_log.h"
+
+#include <string>
+
+#include "uploader/proto/system_profile.pb.h"
+#include "uploader/system_profile_setter.h"
+
+// We use default values for the MetricsLogBase constructor as the setter will
+// override them.
+MetricsLog::MetricsLog()
+    : MetricsLogBase("", 0, metrics::MetricsLogBase::ONGOING_LOG, "") {
+}
+
+void MetricsLog::IncrementUserCrashCount() {
+  metrics::SystemProfileProto::Stability* stability(
+      uma_proto()->mutable_system_profile()->mutable_stability());
+  int current = stability->other_user_crash_count();
+  stability->set_other_user_crash_count(current + 1);
+}
+
+void MetricsLog::IncrementKernelCrashCount() {
+  metrics::SystemProfileProto::Stability* stability(
+      uma_proto()->mutable_system_profile()->mutable_stability());
+  int current = stability->kernel_crash_count();
+  stability->set_kernel_crash_count(current + 1);
+}
+
+void MetricsLog::IncrementUncleanShutdownCount() {
+  metrics::SystemProfileProto::Stability* stability(
+      uma_proto()->mutable_system_profile()->mutable_stability());
+  int current = stability->unclean_system_shutdown_count();
+  stability->set_unclean_system_shutdown_count(current + 1);
+}
+
+void MetricsLog::PopulateSystemProfile(SystemProfileSetter* profile_setter) {
+  profile_setter->Populate(uma_proto());
+}
diff --git a/metricsd/uploader/metrics_log.h b/metricsd/uploader/metrics_log.h
new file mode 100644
index 000000000..a62798fb3
--- /dev/null
+++ b/metricsd/uploader/metrics_log.h
@@ -0,0 +1,42 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_UPLOADER_METRICS_LOG_H_
+#define METRICS_UPLOADER_METRICS_LOG_H_
+
+#include <string>
+
+#include <base/macros.h>
+
+#include "uploader/metrics_log_base.h"
+
+// This file defines a set of user experience metrics data recorded by
+// the MetricsService. This is the unit of data that is sent to the server.
+class SystemProfileSetter;
+
+// This class provides base functionality for logging metrics data.
+class MetricsLog : public metrics::MetricsLogBase {
+ public:
+  // The constructor doesn't set any metadata. The metadata is only set by a
+  // SystemProfileSetter.
+  MetricsLog();
+
+  void IncrementUserCrashCount();
+  void IncrementKernelCrashCount();
+  void IncrementUncleanShutdownCount();
+
+  // Populate the system profile with system information using setter.
+  void PopulateSystemProfile(SystemProfileSetter* setter);
+
+ private:
+  FRIEND_TEST(UploadServiceTest, LogContainsAggregatedValues);
+  FRIEND_TEST(UploadServiceTest, LogKernelCrash);
+  FRIEND_TEST(UploadServiceTest, LogUncleanShutdown);
+  FRIEND_TEST(UploadServiceTest, LogUserCrash);
+  FRIEND_TEST(UploadServiceTest, UnknownCrashIgnored);
+
+  DISALLOW_COPY_AND_ASSIGN(MetricsLog);
+};
+
+#endif  // METRICS_UPLOADER_METRICS_LOG_H_
diff --git a/metricsd/uploader/metrics_log_base.cc b/metricsd/uploader/metrics_log_base.cc
new file mode 100644
index 000000000..3ae01e85a
--- /dev/null
+++ b/metricsd/uploader/metrics_log_base.cc
@@ -0,0 +1,142 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "uploader/metrics_log_base.h"
+
+#include "base/metrics/histogram_base.h"
+#include "base/metrics/histogram_samples.h"
+#include "uploader/metrics_hashes.h"
+#include "uploader/proto/histogram_event.pb.h"
+#include "uploader/proto/system_profile.pb.h"
+#include "uploader/proto/user_action_event.pb.h"
+
+using base::Histogram;
+using base::HistogramBase;
+using base::HistogramSamples;
+using base::SampleCountIterator;
+using base::Time;
+using base::TimeDelta;
+using metrics::HistogramEventProto;
+using metrics::SystemProfileProto;
+using metrics::UserActionEventProto;
+
+namespace metrics {
+namespace {
+
+// Any id less than 16 bytes is considered to be a testing id.
+bool IsTestingID(const std::string& id) {
+  return id.size() < 16;
+}
+
+}  // namespace
+
+MetricsLogBase::MetricsLogBase(const std::string& client_id,
+                               int session_id,
+                               LogType log_type,
+                               const std::string& version_string)
+    : num_events_(0),
+      locked_(false),
+      log_type_(log_type) {
+  DCHECK_NE(NO_LOG, log_type);
+  if (IsTestingID(client_id))
+    uma_proto_.set_client_id(0);
+  else
+    uma_proto_.set_client_id(Hash(client_id));
+
+  uma_proto_.set_session_id(session_id);
+  uma_proto_.mutable_system_profile()->set_build_timestamp(GetBuildTime());
+  uma_proto_.mutable_system_profile()->set_app_version(version_string);
+}
+
+MetricsLogBase::~MetricsLogBase() {}
+
+// static
+uint64_t MetricsLogBase::Hash(const std::string& value) {
+  uint64_t hash = metrics::HashMetricName(value);
+
+  // The following log is VERY helpful when folks add some named histogram into
+  // the code, but forgot to update the descriptive list of histograms.  When
+  // that happens, all we get to see (server side) is a hash of the histogram
+  // name.  We can then use this logging to find out what histogram name was
+  // being hashed to a given MD5 value by just running the version of Chromium
+  // in question with --enable-logging.
+  DVLOG(1) << "Metrics: Hash numeric [" << value << "]=[" << hash << "]";
+
+  return hash;
+}
+
+// static
+int64_t MetricsLogBase::GetBuildTime() {
+  static int64_t integral_build_time = 0;
+  if (!integral_build_time) {
+    Time time;
+    const char* kDateTime = __DATE__ " " __TIME__ " GMT";
+    bool result = Time::FromString(kDateTime, &time);
+    DCHECK(result);
+    integral_build_time = static_cast<int64_t>(time.ToTimeT());
+  }
+  return integral_build_time;
+}
+
+// static
+int64_t MetricsLogBase::GetCurrentTime() {
+  return (base::TimeTicks::Now() - base::TimeTicks()).InSeconds();
+}
+
+void MetricsLogBase::CloseLog() {
+  DCHECK(!locked_);
+  locked_ = true;
+}
+
+void MetricsLogBase::GetEncodedLog(std::string* encoded_log) {
+  DCHECK(locked_);
+  uma_proto_.SerializeToString(encoded_log);
+}
+
+void MetricsLogBase::RecordUserAction(const std::string& key) {
+  DCHECK(!locked_);
+
+  UserActionEventProto* user_action = uma_proto_.add_user_action_event();
+  user_action->set_name_hash(Hash(key));
+  user_action->set_time(GetCurrentTime());
+
+  ++num_events_;
+}
+
+void MetricsLogBase::RecordHistogramDelta(const std::string& histogram_name,
+                                          const HistogramSamples& snapshot) {
+  DCHECK(!locked_);
+  DCHECK_NE(0, snapshot.TotalCount());
+
+  // We will ignore the MAX_INT/infinite value in the last element of range[].
+
+  HistogramEventProto* histogram_proto = uma_proto_.add_histogram_event();
+  histogram_proto->set_name_hash(Hash(histogram_name));
+  histogram_proto->set_sum(snapshot.sum());
+
+  for (scoped_ptr<SampleCountIterator> it = snapshot.Iterator(); !it->Done();
+       it->Next()) {
+    HistogramBase::Sample min;
+    HistogramBase::Sample max;
+    HistogramBase::Count count;
+    it->Get(&min, &max, &count);
+    HistogramEventProto::Bucket* bucket = histogram_proto->add_bucket();
+    bucket->set_min(min);
+    bucket->set_max(max);
+    bucket->set_count(count);
+  }
+
+  // Omit fields to save space (see rules in histogram_event.proto comments).
+  for (int i = 0; i < histogram_proto->bucket_size(); ++i) {
+    HistogramEventProto::Bucket* bucket = histogram_proto->mutable_bucket(i);
+    if (i + 1 < histogram_proto->bucket_size() &&
+        bucket->max() == histogram_proto->bucket(i + 1).min()) {
+      bucket->clear_max();
+    } else if (bucket->max() == bucket->min() + 1) {
+      bucket->clear_min();
+    }
+  }
+}
+
+}  // namespace metrics
diff --git a/metricsd/uploader/metrics_log_base.h b/metricsd/uploader/metrics_log_base.h
new file mode 100644
index 000000000..4173335fb
--- /dev/null
+++ b/metricsd/uploader/metrics_log_base.h
@@ -0,0 +1,110 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This file defines a set of user experience metrics data recorded by
+// the MetricsService.  This is the unit of data that is sent to the server.
+
+#ifndef METRICS_UPLOADER_METRICS_LOG_BASE_H_
+#define METRICS_UPLOADER_METRICS_LOG_BASE_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "base/metrics/histogram.h"
+#include "base/time/time.h"
+#include "uploader/proto/chrome_user_metrics_extension.pb.h"
+
+namespace base {
+class HistogramSamples;
+}  // namespace base
+
+namespace metrics {
+
+// This class provides base functionality for logging metrics data.
+class MetricsLogBase {
+ public:
+  // TODO(asvitkine): Remove the NO_LOG value.
+  enum LogType {
+    INITIAL_STABILITY_LOG,  // The initial log containing stability stats.
+    ONGOING_LOG,            // Subsequent logs in a session.
+    NO_LOG,                 // Placeholder value for when there is no log.
+  };
+
+  // Creates a new metrics log of the specified type.
+  // client_id is the identifier for this profile on this installation
+  // session_id is an integer that's incremented on each application launch
+  MetricsLogBase(const std::string& client_id,
+                 int session_id,
+                 LogType log_type,
+                 const std::string& version_string);
+  virtual ~MetricsLogBase();
+
+  // Computes the MD5 hash of the given string, and returns the first 8 bytes of
+  // the hash.
+  static uint64_t Hash(const std::string& value);
+
+  // Get the GMT buildtime for the current binary, expressed in seconds since
+  // January 1, 1970 GMT.
+  // The value is used to identify when a new build is run, so that previous
+  // reliability stats, from other builds, can be abandoned.
+  static int64_t GetBuildTime();
+
+  // Convenience function to return the current time at a resolution in seconds.
+  // This wraps base::TimeTicks, and hence provides an abstract time that is
+  // always incrementing for use in measuring time durations.
+  static int64_t GetCurrentTime();
+
+  // Records a user-initiated action.
+  void RecordUserAction(const std::string& key);
+
+  // Record any changes in a given histogram for transmission.
+  void RecordHistogramDelta(const std::string& histogram_name,
+                            const base::HistogramSamples& snapshot);
+
+  // Stop writing to this record and generate the encoded representation.
+  // None of the Record* methods can be called after this is called.
+  void CloseLog();
+
+  // Fills |encoded_log| with the serialized protobuf representation of the
+  // record.  Must only be called after CloseLog() has been called.
+  void GetEncodedLog(std::string* encoded_log);
+
+  int num_events() { return num_events_; }
+
+  void set_hardware_class(const std::string& hardware_class) {
+    uma_proto_.mutable_system_profile()->mutable_hardware()->set_hardware_class(
+        hardware_class);
+  }
+
+  LogType log_type() const { return log_type_; }
+
+ protected:
+  bool locked() const { return locked_; }
+
+  metrics::ChromeUserMetricsExtension* uma_proto() { return &uma_proto_; }
+  const metrics::ChromeUserMetricsExtension* uma_proto() const {
+    return &uma_proto_;
+  }
+
+  // TODO(isherman): Remove this once the XML pipeline is outta here.
+  int num_events_;  // the number of events recorded in this log
+
+ private:
+  // locked_ is true when record has been packed up for sending, and should
+  // no longer be written to.  It is only used for sanity checking and is
+  // not a real lock.
+  bool locked_;
+
+  // The type of the log, i.e. initial or ongoing.
+  const LogType log_type_;
+
+  // Stores the protocol buffer representation for this log.
+  metrics::ChromeUserMetricsExtension uma_proto_;
+
+  DISALLOW_COPY_AND_ASSIGN(MetricsLogBase);
+};
+
+}  // namespace metrics
+
+#endif  // METRICS_UPLOADER_METRICS_LOG_BASE_H_
diff --git a/metricsd/uploader/metrics_log_base_unittest.cc b/metricsd/uploader/metrics_log_base_unittest.cc
new file mode 100644
index 000000000..dc03f0032
--- /dev/null
+++ b/metricsd/uploader/metrics_log_base_unittest.cc
@@ -0,0 +1,125 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "uploader/metrics_log_base.h"
+
+#include <string>
+
+#include <base/metrics/bucket_ranges.h>
+#include <base/metrics/sample_vector.h>
+#include <gtest/gtest.h>
+
+#include "uploader/proto/chrome_user_metrics_extension.pb.h"
+
+namespace metrics {
+
+namespace {
+
+class TestMetricsLogBase : public MetricsLogBase {
+ public:
+  TestMetricsLogBase()
+      : MetricsLogBase("client_id", 1, MetricsLogBase::ONGOING_LOG, "1.2.3.4") {
+  }
+  virtual ~TestMetricsLogBase() {}
+
+  using MetricsLogBase::uma_proto;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TestMetricsLogBase);
+};
+
+}  // namespace
+
+TEST(MetricsLogBaseTest, LogType) {
+  MetricsLogBase log1("id", 0, MetricsLogBase::ONGOING_LOG, "1.2.3");
+  EXPECT_EQ(MetricsLogBase::ONGOING_LOG, log1.log_type());
+
+  MetricsLogBase log2("id", 0, MetricsLogBase::INITIAL_STABILITY_LOG, "1.2.3");
+  EXPECT_EQ(MetricsLogBase::INITIAL_STABILITY_LOG, log2.log_type());
+}
+
+TEST(MetricsLogBaseTest, EmptyRecord) {
+  MetricsLogBase log("totally bogus client ID", 137,
+                     MetricsLogBase::ONGOING_LOG, "bogus version");
+  log.set_hardware_class("sample-class");
+  log.CloseLog();
+
+  std::string encoded;
+  log.GetEncodedLog(&encoded);
+
+  // A couple of fields are hard to mock, so these will be copied over directly
+  // for the expected output.
+  metrics::ChromeUserMetricsExtension parsed;
+  ASSERT_TRUE(parsed.ParseFromString(encoded));
+
+  metrics::ChromeUserMetricsExtension expected;
+  expected.set_client_id(5217101509553811875);  // Hashed bogus client ID
+  expected.set_session_id(137);
+  expected.mutable_system_profile()->set_build_timestamp(
+      parsed.system_profile().build_timestamp());
+  expected.mutable_system_profile()->set_app_version("bogus version");
+  expected.mutable_system_profile()->mutable_hardware()->set_hardware_class(
+      "sample-class");
+
+  EXPECT_EQ(expected.SerializeAsString(), encoded);
+}
+
+TEST(MetricsLogBaseTest, HistogramBucketFields) {
+  // Create buckets: 1-5, 5-7, 7-8, 8-9, 9-10, 10-11, 11-12.
+  base::BucketRanges ranges(8);
+  ranges.set_range(0, 1);
+  ranges.set_range(1, 5);
+  ranges.set_range(2, 7);
+  ranges.set_range(3, 8);
+  ranges.set_range(4, 9);
+  ranges.set_range(5, 10);
+  ranges.set_range(6, 11);
+  ranges.set_range(7, 12);
+
+  base::SampleVector samples(&ranges);
+  samples.Accumulate(3, 1);   // Bucket 1-5.
+  samples.Accumulate(6, 1);   // Bucket 5-7.
+  samples.Accumulate(8, 1);   // Bucket 8-9. (7-8 skipped)
+  samples.Accumulate(10, 1);  // Bucket 10-11. (9-10 skipped)
+  samples.Accumulate(11, 1);  // Bucket 11-12.
+
+  TestMetricsLogBase log;
+  log.RecordHistogramDelta("Test", samples);
+
+  const metrics::ChromeUserMetricsExtension* uma_proto = log.uma_proto();
+  const metrics::HistogramEventProto& histogram_proto =
+      uma_proto->histogram_event(uma_proto->histogram_event_size() - 1);
+
+  // Buckets with samples: 1-5, 5-7, 8-9, 10-11, 11-12.
+  // Should become: 1-/, 5-7, /-9, 10-/, /-12.
+  ASSERT_EQ(5, histogram_proto.bucket_size());
+
+  // 1-5 becomes 1-/ (max is same as next min).
+  EXPECT_TRUE(histogram_proto.bucket(0).has_min());
+  EXPECT_FALSE(histogram_proto.bucket(0).has_max());
+  EXPECT_EQ(1, histogram_proto.bucket(0).min());
+
+  // 5-7 stays 5-7 (no optimization possible).
+  EXPECT_TRUE(histogram_proto.bucket(1).has_min());
+  EXPECT_TRUE(histogram_proto.bucket(1).has_max());
+  EXPECT_EQ(5, histogram_proto.bucket(1).min());
+  EXPECT_EQ(7, histogram_proto.bucket(1).max());
+
+  // 8-9 becomes /-9 (min is same as max - 1).
+  EXPECT_FALSE(histogram_proto.bucket(2).has_min());
+  EXPECT_TRUE(histogram_proto.bucket(2).has_max());
+  EXPECT_EQ(9, histogram_proto.bucket(2).max());
+
+  // 10-11 becomes 10-/ (both optimizations apply, omit max is prioritized).
+  EXPECT_TRUE(histogram_proto.bucket(3).has_min());
+  EXPECT_FALSE(histogram_proto.bucket(3).has_max());
+  EXPECT_EQ(10, histogram_proto.bucket(3).min());
+
+  // 11-12 becomes /-12 (last record must keep max, min is same as max - 1).
+  EXPECT_FALSE(histogram_proto.bucket(4).has_min());
+  EXPECT_TRUE(histogram_proto.bucket(4).has_max());
+  EXPECT_EQ(12, histogram_proto.bucket(4).max());
+}
+
+}  // namespace metrics
diff --git a/metricsd/uploader/mock/mock_system_profile_setter.h b/metricsd/uploader/mock/mock_system_profile_setter.h
new file mode 100644
index 000000000..c6e8f0d1e
--- /dev/null
+++ b/metricsd/uploader/mock/mock_system_profile_setter.h
@@ -0,0 +1,20 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_UPLOADER_MOCK_MOCK_SYSTEM_PROFILE_SETTER_H_
+#define METRICS_UPLOADER_MOCK_MOCK_SYSTEM_PROFILE_SETTER_H_
+
+#include "uploader/system_profile_setter.h"
+
+namespace metrics {
+class ChromeUserMetricsExtension;
+}
+
+// Mock profile setter used for testing.
+class MockSystemProfileSetter : public SystemProfileSetter {
+ public:
+  void Populate(metrics::ChromeUserMetricsExtension* profile_proto) override {}
+};
+
+#endif  // METRICS_UPLOADER_MOCK_MOCK_SYSTEM_PROFILE_SETTER_H_
diff --git a/metricsd/uploader/mock/sender_mock.cc b/metricsd/uploader/mock/sender_mock.cc
new file mode 100644
index 000000000..064ec6d01
--- /dev/null
+++ b/metricsd/uploader/mock/sender_mock.cc
@@ -0,0 +1,24 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "uploader/mock/sender_mock.h"
+
+SenderMock::SenderMock() {
+  Reset();
+}
+
+bool SenderMock::Send(const std::string& content, const std::string& hash) {
+  send_call_count_ += 1;
+  last_message_ = content;
+  is_good_proto_ = last_message_proto_.ParseFromString(content);
+  return should_succeed_;
+}
+
+void SenderMock::Reset() {
+  send_call_count_ = 0;
+  last_message_ = "";
+  should_succeed_ = true;
+  last_message_proto_.Clear();
+  is_good_proto_ = false;
+}
diff --git a/metricsd/uploader/mock/sender_mock.h b/metricsd/uploader/mock/sender_mock.h
new file mode 100644
index 000000000..0a15d6163
--- /dev/null
+++ b/metricsd/uploader/mock/sender_mock.h
@@ -0,0 +1,48 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_UPLOADER_MOCK_SENDER_MOCK_H_
+#define METRICS_UPLOADER_MOCK_SENDER_MOCK_H_
+
+#include <string>
+
+#include "base/compiler_specific.h"
+#include "uploader/proto/chrome_user_metrics_extension.pb.h"
+#include "uploader/sender.h"
+
+class SenderMock : public Sender {
+ public:
+  SenderMock();
+
+  bool Send(const std::string& content, const std::string& hash) override;
+  void Reset();
+
+  bool is_good_proto() { return is_good_proto_; }
+  int send_call_count() { return send_call_count_; }
+  const std::string last_message() { return last_message_; }
+  metrics::ChromeUserMetricsExtension last_message_proto() {
+    return last_message_proto_;
+  }
+  void set_should_succeed(bool succeed) { should_succeed_ = succeed; }
+
+ private:
+  // Is set to true if the proto was parsed successfully.
+  bool is_good_proto_;
+
+  // If set to true, the Send method will return true to simulate a successful
+  // send.
+  bool should_succeed_;
+
+  // Count of how many times Send was called since the last reset.
+  int send_call_count_;
+
+  // Last message received by Send.
+  std::string last_message_;
+
+  // If is_good_proto is true, last_message_proto is the deserialized
+  // representation of last_message.
+  metrics::ChromeUserMetricsExtension last_message_proto_;
+};
+
+#endif  // METRICS_UPLOADER_MOCK_SENDER_MOCK_H_
diff --git a/metricsd/uploader/proto/README b/metricsd/uploader/proto/README
new file mode 100644
index 000000000..9bd3249b0
--- /dev/null
+++ b/metricsd/uploader/proto/README
@@ -0,0 +1,25 @@
+Copyright 2015 The Chromium OS Authors. All rights reserved.
+Use of this source code is governed by a BSD-style license that can be
+found in the LICENSE file.
+
+
+This directory contains the protocol buffers used by the standalone metrics
+uploader. Those protobuffers are copied from the chromium protobuffers from
+https://chromium.googlesource.com/chromium/src/+/master/components/metrics/proto/
+at 3bfe5f2b4c03d2cac718d137ed14cd2c6354bfed.
+
+Any change to this protobuf must first be made to the backend's protobuf and be
+compatible with the chromium protobuffers.
+
+
+Q: Why fork the chromium protobuffers ?
+A: The standalone metrics uploader needs chromium os fields that are not defined
+by the chromium protobufs. Instead of pushing chromium os specific changes to
+chromium, we can add them only to chromium os (and to the backend of course).
+
+
+Q: What's the difference between those protobuffers and chromium's protobuffers?
+A: When the protobuffers were copied, some chromium specific protobuffers were
+not imported:
+* omnibox related protobuffers.
+* performance profiling protobuffers (not used in chromium os).
diff --git a/metricsd/uploader/proto/chrome_user_metrics_extension.proto b/metricsd/uploader/proto/chrome_user_metrics_extension.proto
new file mode 100644
index 000000000..d4d4f240b
--- /dev/null
+++ b/metricsd/uploader/proto/chrome_user_metrics_extension.proto
@@ -0,0 +1,60 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Protocol buffer for Chrome UMA (User Metrics Analysis).
+//
+// Note: this protobuf must be compatible with the one in chromium.
+
+syntax = "proto2";
+
+option optimize_for = LITE_RUNTIME;
+option java_outer_classname = "ChromeUserMetricsExtensionProtos";
+option java_package = "org.chromium.components.metrics";
+
+package metrics;
+
+import "system/core/metricsd/uploader/proto/histogram_event.proto";
+import "system/core/metricsd/uploader/proto/system_profile.proto";
+import "system/core/metricsd/uploader/proto/user_action_event.proto";
+
+// Next tag: 13
+message ChromeUserMetricsExtension {
+  // The product (i.e. end user application) for a given UMA log.
+  enum Product {
+    // Google Chrome product family.
+    CHROME = 0;
+  }
+  // The product corresponding to this log. The field type is int32 instead of
+  // Product so that downstream users of the Chromium metrics component can
+  // introduce products without needing to make changes to the Chromium code
+  // (though they still need to add the new product to the server-side enum).
+  // Note: The default value is Chrome, so Chrome products will not transmit
+  // this field.
+  optional int32 product = 10 [default = 0];
+
+  // The id of the client install that generated these events.
+  //
+  // For Chrome clients, this id is unique to a top-level (one level above the
+  // "Default" directory) Chrome user data directory [1], and so is shared among
+  // all Chrome user profiles contained in this user data directory.
+  // An id of 0 is reserved for test data (monitoring and internal testing) and
+  // should normally be ignored in analysis of the data.
+  // [1] http://www.chromium.org/user-experience/user-data-directory
+  optional fixed64 client_id = 1;
+
+  // The session id for this user.
+  // Values such as tab ids are only meaningful within a particular session.
+  // The client keeps track of the session id and sends it with each event.
+  // The session id is simply an integer that is incremented each time the user
+  // relaunches Chrome.
+  optional int32 session_id = 2;
+
+  // Information about the user's browser and system configuration.
+  optional SystemProfileProto system_profile = 3;
+
+  // This message will log one or more of the following event types:
+  repeated UserActionEventProto user_action_event = 4;
+  repeated HistogramEventProto histogram_event = 6;
+
+}
diff --git a/metricsd/uploader/proto/histogram_event.proto b/metricsd/uploader/proto/histogram_event.proto
new file mode 100644
index 000000000..4b68094ff
--- /dev/null
+++ b/metricsd/uploader/proto/histogram_event.proto
@@ -0,0 +1,47 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Histogram-collected metrics.
+
+syntax = "proto2";
+
+option optimize_for = LITE_RUNTIME;
+option java_outer_classname = "HistogramEventProtos";
+option java_package = "org.chromium.components.metrics";
+
+package metrics;
+
+// Next tag: 4
+message HistogramEventProto {
+  // The name of the histogram, hashed.
+  optional fixed64 name_hash = 1;
+
+  // The sum of all the sample values.
+  // Together with the total count of the sample values, this allows us to
+  // compute the average value.  The count of all sample values is just the sum
+  // of the counts of all the buckets.
+  optional int64 sum = 2;
+
+  // The per-bucket data.
+  message Bucket {
+    // Each bucket's range is bounded by min <= x < max.
+    // It is valid to omit one of these two fields in a bucket, but not both.
+    // If the min field is omitted, its value is assumed to be equal to max - 1.
+    // If the max field is omitted, its value is assumed to be equal to the next
+    // bucket's min value (possibly computed per above).  The last bucket in a
+    // histogram should always include the max field.
+    optional int64 min = 1;
+    optional int64 max = 2;
+
+    // The bucket's index in the list of buckets, sorted in ascending order.
+    // This field was intended to provide extra redundancy to detect corrupted
+    // records, but was never used.  As of M31, it is no longer sent by Chrome
+    // clients to reduce the UMA upload size.
+    optional int32 bucket_index = 3 [deprecated = true];
+
+    // The number of entries in this bucket.
+    optional int64 count = 4;
+  }
+  repeated Bucket bucket = 3;
+}
diff --git a/metricsd/uploader/proto/system_profile.proto b/metricsd/uploader/proto/system_profile.proto
new file mode 100644
index 000000000..d33ff6097
--- /dev/null
+++ b/metricsd/uploader/proto/system_profile.proto
@@ -0,0 +1,747 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Stores information about the user's brower and system configuration.
+// The system configuration fields are recorded once per client session.
+
+syntax = "proto2";
+
+option optimize_for = LITE_RUNTIME;
+option java_outer_classname = "SystemProfileProtos";
+option java_package = "org.chromium.components.metrics";
+
+package metrics;
+
+// Next tag: 21
+message SystemProfileProto {
+  // The time when the client was compiled/linked, in seconds since the epoch.
+  optional int64 build_timestamp = 1;
+
+  // A version number string for the application.
+  // Most commonly this is the browser version number found in a user agent
+  // string, and is typically a 4-tuple of numbers separated by periods.  In
+  // cases where the user agent version might be ambiguous (example: Linux 64-
+  // bit build, rather than 32-bit build, or a Windows version used in some
+  // special context, such as ChromeFrame running in IE), then this may include
+  // some additional postfix to provide clarification not available in the UA
+  // string.
+  //
+  // An example of a browser version 4-tuple is "5.0.322.0".  Currently used
+  // postfixes are:
+  //
+  //   "-64": a 64-bit build
+  //   "-F": Chrome is running under control of ChromeFrame
+  //   "-devel": this is not an official build of Chrome
+  //
+  // A full version number string could look similar to:
+  // "5.0.322.0-F-devel".
+  //
+  // This value, when available, is more trustworthy than the UA string
+  // associated with the request; and including the postfix, may be more
+  // specific.
+  optional string app_version = 2;
+
+  // The brand code or distribution tag assigned to a partner, if available.
+  // Brand codes are only available on Windows.  Not every Windows install
+  // though will have a brand code.
+  optional string brand_code = 12;
+
+  // The possible channels for an installation, from least to most stable.
+  enum Channel {
+    CHANNEL_UNKNOWN = 0;  // Unknown channel -- perhaps an unofficial build?
+    CHANNEL_CANARY = 1;
+    CHANNEL_DEV = 2;
+    CHANNEL_BETA = 3;
+    CHANNEL_STABLE = 4;
+  }
+  optional Channel channel = 10;
+
+  // True if Chrome build is ASan-instrumented.
+  optional bool is_asan_build = 20 [default = false];
+
+  // The date the user enabled UMA, in seconds since the epoch.
+  // If the user has toggled the UMA enabled state multiple times, this will
+  // be the most recent date on which UMA was enabled.
+  // For privacy, this is rounded to the nearest hour.
+  optional int64 uma_enabled_date = 3;
+
+  // The time when the client was installed, in seconds since the epoch.
+  // For privacy, this is rounded to the nearest hour.
+  optional int64 install_date = 16;
+
+  // The user's selected application locale, i.e. the user interface language.
+  // The locale includes a language code and, possibly, also a country code,
+  // e.g. "en-US".
+  optional string application_locale = 4;
+
+  message BrilloDeviceData {
+    optional string build_target_id = 1;
+  }
+  optional BrilloDeviceData brillo = 21;
+
+  // Information on the user's operating system.
+  message OS {
+    // The user's operating system. This should be one of:
+    // - Android
+    // - Windows NT
+    // - Linux (includes ChromeOS)
+    // - iPhone OS
+    // - Mac OS X
+    optional string name = 1;
+
+    // The version of the OS.  The meaning of this field is OS-dependent.
+    optional string version = 2;
+
+    // The fingerprint of the build.  This field is used only on Android.
+    optional string fingerprint = 3;
+
+    // Whether the version of iOS appears to be "jailbroken". This field is
+    // used only on iOS. Chrome for iOS detects whether device contains a
+    // DynamicLibraries/ directory. It's a necessary but insufficient indicator
+    // of whether the operating system has been jailbroken.
+    optional bool is_jailbroken = 4;
+  }
+  optional OS os = 5;
+
+  // Next tag for Hardware: 18
+  // Information on the user's hardware.
+  message Hardware {
+    // The CPU architecture (x86, PowerPC, x86_64, ...)
+    optional string cpu_architecture = 1;
+
+    // The amount of RAM present on the system, in megabytes.
+    optional int64 system_ram_mb = 2;
+
+    // The base memory address that chrome.dll was loaded at.
+    // (Logged only on Windows.)
+    optional int64 dll_base = 3;
+
+    // The Chrome OS device hardware class ID is a unique string associated with
+    // each Chrome OS device product revision generally assigned at hardware
+    // qualification time.  The hardware class effectively identifies the
+    // configured system components such as CPU, WiFi adapter, etc.
+    //
+    // An example of such a hardware class is "IEC MARIO PONY 6101".  An
+    // internal database associates this hardware class with the qualified
+    // device specifications including OEM information, schematics, hardware
+    // qualification reports, test device tags, etc.
+    optional string hardware_class = 4;
+
+    // The number of physical screens.
+    optional int32 screen_count = 5;
+
+    // The screen dimensions of the primary screen, in pixels.
+    optional int32 primary_screen_width = 6;
+    optional int32 primary_screen_height = 7;
+
+    // The device scale factor of the primary screen.
+    optional float primary_screen_scale_factor = 12;
+
+    // Max DPI for any attached screen. (Windows only)
+    optional float max_dpi_x = 9;
+    optional float max_dpi_y = 10;
+
+    // Information on the CPU obtained by CPUID.
+    message CPU {
+      // A 12 character string naming the vendor, e.g. "GeniuneIntel".
+      optional string vendor_name = 1;
+
+      // The signature reported by CPUID (from EAX).
+      optional uint32 signature = 2;
+
+      // Number of logical processors/cores on the current machine.
+      optional uint32 num_cores = 3;
+    }
+    optional CPU cpu = 13;
+
+    // Information on the GPU
+    message Graphics {
+      // The GPU manufacturer's vendor id.
+      optional uint32 vendor_id = 1;
+
+      // The GPU manufacturer's device id for the chip set.
+      optional uint32 device_id = 2;
+
+      // The driver version on the GPU.
+      optional string driver_version = 3;
+
+      // The driver date on the GPU.
+      optional string driver_date = 4;
+
+      // The GL_VENDOR string. An example of a gl_vendor string is
+      // "Imagination Technologies". "" if we are not using OpenGL.
+      optional string gl_vendor = 6;
+
+      // The GL_RENDERER string. An example of a gl_renderer string is
+      // "PowerVR SGX 540". "" if we are not using OpenGL.
+      optional string gl_renderer = 7;
+    }
+    optional Graphics gpu = 8;
+
+    // Information about Bluetooth devices paired with the system.
+    message Bluetooth {
+      // Whether Bluetooth is present on this system.
+      optional bool is_present = 1;
+
+      // Whether Bluetooth is enabled on this system.
+      optional bool is_enabled = 2;
+
+      // Describes a paired device.
+      message PairedDevice {
+        // Assigned class of the device. This is a bitfield according to the
+        // Bluetooth specification available at the following URL:
+        // https://www.bluetooth.org/en-us/specification/assigned-numbers-overview/baseband
+        optional uint32 bluetooth_class = 1;
+
+        // Decoded device type.
+        enum Type {
+          DEVICE_UNKNOWN = 0;
+          DEVICE_COMPUTER = 1;
+          DEVICE_PHONE = 2;
+          DEVICE_MODEM = 3;
+          DEVICE_AUDIO = 4;
+          DEVICE_CAR_AUDIO = 5;
+          DEVICE_VIDEO = 6;
+          DEVICE_PERIPHERAL = 7;
+          DEVICE_JOYSTICK = 8;
+          DEVICE_GAMEPAD = 9;
+          DEVICE_KEYBOARD = 10;
+          DEVICE_MOUSE = 11;
+          DEVICE_TABLET = 12;
+          DEVICE_KEYBOARD_MOUSE_COMBO = 13;
+        }
+        optional Type type = 2;
+
+        // Vendor prefix of the Bluetooth address, these are OUI registered by
+        // the IEEE and are encoded with the first byte in bits 16-23, the
+        // second byte in bits 8-15 and the third byte in bits 0-7.
+        //
+        // ie. Google's OUI (00:1A:11) is encoded as 0x00001A11
+        optional uint32 vendor_prefix = 4;
+
+        // The Vendor ID of a device, returned in vendor_id below, can be
+        // either allocated by the Bluetooth SIG or USB IF, providing two
+        // completely overlapping namespaces for identifiers.
+        //
+        // This field should be read along with vendor_id to correctly
+        // identify the vendor. For example Google is identified by either
+        // vendor_id_source = VENDOR_ID_BLUETOOTH, vendor_id = 0x00E0 or
+        // vendor_id_source = VENDOR_ID_USB, vendor_id = 0x18D1.
+        //
+        // If the device does not support the Device ID specification the
+        // unknown value will be set.
+        enum VendorIDSource {
+          VENDOR_ID_UNKNOWN = 0;
+          VENDOR_ID_BLUETOOTH = 1;
+          VENDOR_ID_USB = 2;
+        }
+        optional VendorIDSource vendor_id_source = 8;
+
+        // Vendor ID of the device, where available.
+        optional uint32 vendor_id = 5;
+
+        // Product ID of the device, where available.
+        optional uint32 product_id = 6;
+
+        // Device ID of the device, generally the release or version number in
+        // BCD format, where available.
+        optional uint32 device_id = 7;
+      }
+      repeated PairedDevice paired_device = 3;
+    }
+    optional Bluetooth bluetooth = 11;
+
+    // Whether the internal display produces touch events. Omitted if unknown.
+    // Logged on ChromeOS only.
+    optional bool internal_display_supports_touch = 14;
+
+    // Vendor ids and product ids of external touchscreens.
+    message TouchScreen {
+      // Touch screen vendor id.
+      optional uint32 vendor_id = 1;
+      // Touch screen product id.
+      optional uint32 product_id = 2;
+    }
+    // Lists vendor and product ids of external touchscreens.
+    // Logged on ChromeOS only.
+    repeated TouchScreen external_touchscreen = 15;
+
+    // Drive messages are currently logged on Windows 7+, iOS, and Android.
+    message Drive {
+      // Whether this drive incurs a time penalty when randomly accessed. This
+      // should be true for spinning disks but false for SSDs or other
+      // flash-based drives.
+      optional bool has_seek_penalty = 1;
+    }
+    // The drive that the application executable was loaded from.
+    optional Drive app_drive = 16;
+    // The drive that the current user data directory was loaded from.
+    optional Drive user_data_drive = 17;
+  }
+  optional Hardware hardware = 6;
+
+  // Information about the network connection.
+  message Network {
+    // Set to true if connection_type changed during the lifetime of the log.
+    optional bool connection_type_is_ambiguous = 1;
+
+    // See net::NetworkChangeNotifier::ConnectionType.
+    enum ConnectionType {
+      CONNECTION_UNKNOWN = 0;
+      CONNECTION_ETHERNET = 1;
+      CONNECTION_WIFI = 2;
+      CONNECTION_2G = 3;
+      CONNECTION_3G = 4;
+      CONNECTION_4G = 5;
+      CONNECTION_BLUETOOTH = 6;
+    }
+    // The connection type according to NetworkChangeNotifier.
+    optional ConnectionType connection_type = 2;
+
+    // Set to true if wifi_phy_layer_protocol changed during the lifetime of the log.
+    optional bool wifi_phy_layer_protocol_is_ambiguous = 3;
+
+    // See net::WifiPHYLayerProtocol.
+    enum WifiPHYLayerProtocol {
+      WIFI_PHY_LAYER_PROTOCOL_NONE = 0;
+      WIFI_PHY_LAYER_PROTOCOL_ANCIENT = 1;
+      WIFI_PHY_LAYER_PROTOCOL_A = 2;
+      WIFI_PHY_LAYER_PROTOCOL_B = 3;
+      WIFI_PHY_LAYER_PROTOCOL_G = 4;
+      WIFI_PHY_LAYER_PROTOCOL_N = 5;
+      WIFI_PHY_LAYER_PROTOCOL_UNKNOWN = 6;
+    }
+    // The physical layer mode of the associated wifi access point, if any.
+    optional WifiPHYLayerProtocol wifi_phy_layer_protocol = 4;
+
+    // Describe wifi access point information.
+    message WifiAccessPoint {
+      // Vendor prefix of the access point's BSSID, these are OUIs
+      // (Organizationally Unique Identifiers) registered by
+      // the IEEE and are encoded with the first byte in bits 16-23, the
+      // second byte in bits 8-15 and the third byte in bits 0-7.
+      optional uint32 vendor_prefix = 1;
+
+      // Access point seurity mode definitions.
+      enum SecurityMode {
+        SECURITY_UNKNOWN = 0;
+        SECURITY_WPA = 1;
+        SECURITY_WEP = 2;
+        SECURITY_RSN = 3;
+        SECURITY_802_1X = 4;
+        SECURITY_PSK = 5;
+        SECURITY_NONE = 6;
+      }
+      // The security mode of the access point.
+      optional SecurityMode security_mode = 2;
+
+      // Vendor specific information.
+      message VendorInformation {
+        // The model number, for example "0".
+        optional string model_number = 1;
+
+        // The model name (sometimes the same as the model_number),
+        // for example "WZR-HP-AG300H".
+        optional string model_name = 2;
+
+        // The device name (sometimes the same as the model_number),
+        // for example "Dummynet"
+        optional string device_name = 3;
+
+        // The list of vendor-specific OUIs (Organziationally Unqiue
+        // Identifiers). These are provided by the vendor through WPS
+        // (Wireless Provisioning Service) information elements, which
+        // identifies the content of the element.
+        repeated uint32 element_identifier = 4;
+      }
+      // The wireless access point vendor information.
+      optional VendorInformation vendor_info = 3;
+    }
+    // Information of the wireless AP that device is connected to.
+    optional WifiAccessPoint access_point_info = 5;
+  }
+  optional Network network = 13;
+
+  // Information on the Google Update install that is managing this client.
+  message GoogleUpdate {
+    // Whether the Google Update install is system-level or user-level.
+    optional bool is_system_install = 1;
+
+    // The date at which Google Update last started performing an automatic
+    // update check, in seconds since the Unix epoch.
+    optional int64 last_automatic_start_timestamp = 2;
+
+    // The date at which Google Update last successfully sent an update check
+    // and recieved an intact response from the server, in seconds since the
+    // Unix epoch. (The updates don't need to be successfully installed.)
+    optional int64 last_update_check_timestamp = 3;
+
+    // Describes a product being managed by Google Update. (This can also
+    // describe Google Update itself.)
+    message ProductInfo {
+      // The current version of the product that is installed.
+      optional string version = 1;
+
+      // The date at which Google Update successfully updated this product,
+      // stored in seconds since the Unix epoch.  This is updated when an update
+      // is successfully applied, or if the server reports that no update
+      // is available.
+      optional int64 last_update_success_timestamp = 2;
+
+      // The result reported by the product updater on its last run.
+      enum InstallResult {
+        INSTALL_RESULT_SUCCESS = 0;
+        INSTALL_RESULT_FAILED_CUSTOM_ERROR = 1;
+        INSTALL_RESULT_FAILED_MSI_ERROR = 2;
+        INSTALL_RESULT_FAILED_SYSTEM_ERROR = 3;
+        INSTALL_RESULT_EXIT_CODE = 4;
+      }
+      optional InstallResult last_result = 3;
+
+      // The error code reported by the product updater on its last run.  This
+      // will typically be a error code specific to the product installer.
+      optional int32 last_error = 4;
+
+      // The extra error code reported by the product updater on its last run.
+      // This will typically be a Win32 error code.
+      optional int32 last_extra_error = 5;
+    }
+    optional ProductInfo google_update_status = 4;
+    optional ProductInfo client_status = 5;
+  }
+  optional GoogleUpdate google_update = 11;
+
+  // Information on all installed plugins.
+  message Plugin {
+    // The plugin's self-reported name and filename (without path).
+    optional string name = 1;
+    optional string filename = 2;
+
+    // The plugin's version.
+    optional string version = 3;
+
+    // True if the plugin is disabled.
+    // If a client has multiple local Chrome user accounts, this is logged based
+    // on the first user account launched during the current session.
+    optional bool is_disabled = 4;
+
+    // True if the plugin is PPAPI.
+    optional bool is_pepper = 5;
+  }
+  repeated Plugin plugin = 7;
+
+  // Figures that can be used to generate application stability metrics.
+  // All values are counts of events since the last time that these
+  // values were reported.
+  // Next tag: 24
+  message Stability {
+    // Total amount of time that the program was running, in seconds,
+    // since the last time a log was recorded, as measured using a client-side
+    // clock implemented via TimeTicks, which guarantees that it is monotonic
+    // and does not jump if the user changes his/her clock.  The TimeTicks
+    // implementation also makes the clock not count time the computer is
+    // suspended.
+    optional int64 incremental_uptime_sec = 1;
+
+    // Total amount of time that the program was running, in seconds,
+    // since startup, as measured using a client-side clock implemented
+    // via TimeTicks, which guarantees that it is monotonic and does not
+    // jump if the user changes his/her clock.  The TimeTicks implementation
+    // also makes the clock not count time the computer is suspended.
+    // This field was added for M-35.
+    optional int64 uptime_sec = 23;
+
+    // Page loads along with renderer crashes and hangs, since page load count
+    // roughly corresponds to usage.
+    optional int32 page_load_count = 2;
+    optional int32 renderer_crash_count = 3;
+    optional int32 renderer_hang_count = 4;
+
+    // Number of renderer crashes that were for extensions. These crashes are
+    // not counted in renderer_crash_count.
+    optional int32 extension_renderer_crash_count = 5;
+
+    // Number of non-renderer child process crashes.
+    optional int32 child_process_crash_count = 6;
+
+    // Number of times the browser has crashed while logged in as the "other
+    // user" (guest) account.
+    // Logged on ChromeOS only.
+    optional int32 other_user_crash_count = 7;
+
+    // Number of times the kernel has crashed.
+    // Logged on ChromeOS only.
+    optional int32 kernel_crash_count = 8;
+
+    // Number of times the system has shut down uncleanly.
+    // Logged on ChromeOS only.
+    optional int32 unclean_system_shutdown_count = 9;
+
+    //
+    // All the remaining fields in the Stability are recorded at most once per
+    // client session.
+    //
+
+    // The number of times the program was launched.
+    // This will typically be equal to 1.  However, it is possible that Chrome
+    // was unable to upload stability metrics for previous launches (e.g. due to
+    // crashing early during startup), and hence this value might be greater
+    // than 1.
+    optional int32 launch_count = 15;
+    // The number of times that it didn't exit cleanly (which we assume to be
+    // mostly crashes).
+    optional int32 crash_count = 16;
+
+    // The number of times the program began, but did not complete, the shutdown
+    // process.  (For example, this may occur when Windows is shutting down, and
+    // it only gives the process a few seconds to clean up.)
+    optional int32 incomplete_shutdown_count = 17;
+
+    // The number of times the program was able register with breakpad crash
+    // services.
+    optional int32 breakpad_registration_success_count = 18;
+
+    // The number of times the program failed to register with breakpad crash
+    // services.  If crash registration fails then when the program crashes no
+    // crash report will be generated.
+    optional int32 breakpad_registration_failure_count = 19;
+
+    // The number of times the program has run under a debugger.  This should
+    // be an exceptional condition.  Running under a debugger prevents crash
+    // dumps from being generated.
+    optional int32 debugger_present_count = 20;
+
+    // The number of times the program has run without a debugger attached.
+    // This should be most common scenario and should be very close to
+    // |launch_count|.
+    optional int32 debugger_not_present_count = 21;
+
+    // Stability information for all installed plugins.
+    message PluginStability {
+      // The relevant plugin's information (name, etc.)
+      optional Plugin plugin = 1;
+
+      // The number of times this plugin's process was launched.
+      optional int32 launch_count = 2;
+
+      // The number of times this plugin was instantiated on a web page.
+      // This will be >= |launch_count|.
+      // (A page load with multiple sections drawn by this plugin will
+      // increase this count multiple times.)
+      optional int32 instance_count = 3;
+
+      // The number of times this plugin process crashed.
+      // This value will be <= |launch_count|.
+      optional int32 crash_count = 4;
+
+      // The number of times this plugin could not be loaded.
+      optional int32 loading_error_count = 5;
+    }
+    repeated PluginStability plugin_stability = 22;
+  }
+  optional Stability stability = 8;
+
+  // Description of a field trial or experiment that the user is currently
+  // enrolled in.
+  // All metrics reported in this upload can potentially be influenced by the
+  // field trial.
+  message FieldTrial {
+    // The name of the field trial, as a 32-bit identifier.
+    // Currently, the identifier is a hash of the field trial's name.
+    optional fixed32 name_id = 1;
+
+    // The user's group within the field trial, as a 32-bit identifier.
+    // Currently, the identifier is a hash of the group's name.
+    optional fixed32 group_id = 2;
+  }
+  repeated FieldTrial field_trial = 9;
+
+  // Information about the A/V output device(s) (typically just a TV).
+  // However, a configuration may have one or more intermediate A/V devices
+  // between the source device and the TV (e.g. an A/V receiver, video
+  // processor, etc.).
+  message ExternalAudioVideoDevice {
+    // The manufacturer name (possibly encoded as a 3-letter code, e.g. "YMH"
+    // for Yamaha).
+    optional string manufacturer_name = 1;
+
+    // The model name (e.g. "RX-V1900"). Some devices may report generic names
+    // like "receiver" or use the full manufacturer name (e.g "PHILIPS").
+    optional string model_name = 2;
+
+    // The product code (e.g. "0218").
+    optional string product_code = 3;
+
+    // The device types. A single device can have multiple types (e.g. a set-top
+    // box could be both a tuner and a player).  The same type may even be
+    // repeated (e.g a device that reports two tuners).
+    enum AVDeviceType {
+      AV_DEVICE_TYPE_UNKNOWN = 0;
+      AV_DEVICE_TYPE_TV = 1;
+      AV_DEVICE_TYPE_RECORDER = 2;
+      AV_DEVICE_TYPE_TUNER = 3;
+      AV_DEVICE_TYPE_PLAYER = 4;
+      AV_DEVICE_TYPE_AUDIO_SYSTEM = 5;
+    }
+    repeated AVDeviceType av_device_type = 4;
+
+    // The year of manufacture.
+    optional int32 manufacture_year = 5;
+
+    // The week of manufacture.
+    // Note: per the Wikipedia EDID article, numbering for this field may not
+    // be consistent between manufacturers.
+    optional int32 manufacture_week = 6;
+
+    // Max horizontal resolution in pixels.
+    optional int32 horizontal_resolution = 7;
+
+    // Max vertical resolution in pixels.
+    optional int32 vertical_resolution = 8;
+
+    // Audio capabilities of the device.
+    // Ref: http://en.wikipedia.org/wiki/Extended_display_identification_data
+    message AudioDescription {
+      // Audio format
+      enum AudioFormat {
+        AUDIO_FORMAT_UNKNOWN = 0;
+        AUDIO_FORMAT_LPCM = 1;
+        AUDIO_FORMAT_AC_3 = 2;
+        AUDIO_FORMAT_MPEG1 = 3;
+        AUDIO_FORMAT_MP3 = 4;
+        AUDIO_FORMAT_MPEG2 = 5;
+        AUDIO_FORMAT_AAC = 6;
+        AUDIO_FORMAT_DTS = 7;
+        AUDIO_FORMAT_ATRAC = 8;
+        AUDIO_FORMAT_ONE_BIT = 9;
+        AUDIO_FORMAT_DD_PLUS = 10;
+        AUDIO_FORMAT_DTS_HD = 11;
+        AUDIO_FORMAT_MLP_DOLBY_TRUEHD = 12;
+        AUDIO_FORMAT_DST_AUDIO = 13;
+        AUDIO_FORMAT_MICROSOFT_WMA_PRO = 14;
+      }
+      optional AudioFormat audio_format = 1;
+
+      // Number of channels (e.g. 1, 2, 8, etc.).
+      optional int32 num_channels = 2;
+
+      // Supported sample frequencies in Hz (e.g. 32000, 44100, etc.).
+      // Multiple frequencies may be specified.
+      repeated int32 sample_frequency_hz = 3;
+
+      // Maximum bit rate in bits/s.
+      optional int32 max_bit_rate_per_second = 4;
+
+      // Bit depth (e.g. 16, 20, 24, etc.).
+      optional int32 bit_depth = 5;
+    }
+    repeated AudioDescription audio_description = 9;
+
+    // The position in AV setup.
+    // A value of 0 means this device is the TV.
+    // A value of 1 means this device is directly connected to one of
+    // the TV's inputs.
+    // Values > 1 indicate there are 1 or more devices between this device
+    // and the TV.
+    optional int32 position_in_setup = 10;
+
+    // Whether this device is in the path to the TV.
+    optional bool is_in_path_to_tv = 11;
+
+    // The CEC version the device supports.
+    // CEC stands for Consumer Electronics Control, a part of the HDMI
+    // specification.  Not all HDMI devices support CEC.
+    // Only devices that support CEC will report a value here.
+    optional int32 cec_version = 12;
+
+    // This message reports CEC commands seen by a device.
+    // After each log is sent, this information is cleared and gathered again.
+    // By collecting CEC status information by opcode we can determine
+    // which CEC features can be supported.
+    message CECCommand {
+      // The CEC command opcode.  CEC supports up to 256 opcodes.
+      // We add only one CECCommand message per unique opcode.  Only opcodes
+      // seen by the device will be reported. The remainder of the message
+      // accumulates status for this opcode (and device).
+      optional int32 opcode = 1;
+
+      // The total number of commands received from the external device.
+      optional int32 num_received_direct = 2;
+
+      // The number of commands received from the external device as part of a
+      // broadcast message.
+      optional int32 num_received_broadcast = 3;
+
+      // The total number of commands sent to the external device.
+      optional int32 num_sent_direct = 4;
+
+      // The number of commands sent to the external device as part of a
+      // broadcast message.
+      optional int32 num_sent_broadcast = 5;
+
+      // The number of aborted commands for unknown reasons.
+      optional int32 num_aborted_unknown_reason = 6;
+
+      // The number of aborted commands because of an unrecognized opcode.
+      optional int32 num_aborted_unrecognized = 7;
+    }
+    repeated CECCommand cec_command = 13;
+  }
+  repeated ExternalAudioVideoDevice external_audio_video_device = 14;
+
+  // Information about the current wireless access point. Collected directly
+  // from the wireless access point via standard apis if the device is
+  // connected to the Internet wirelessly. Introduced for Chrome on TV devices
+  // but also can be collected by ChromeOS, Android or other clients.
+  message ExternalAccessPoint {
+    // The manufacturer name, for example "ASUSTeK Computer Inc.".
+    optional string manufacturer = 1;
+
+    // The model name, for example "Wi-Fi Protected Setup Router".
+    optional string model_name = 2;
+
+    // The model number, for example "RT-N16".
+    optional string model_number = 3;
+
+    // The device name (sometime same as model_number), for example "RT-N16".
+    optional string device_name = 4;
+  }
+  optional ExternalAccessPoint external_access_point = 15;
+
+  // Number of users currently signed into a multiprofile session.
+  // A zero value indicates that the user count changed while the log is open.
+  // Logged only on ChromeOS.
+  optional uint32 multi_profile_user_count = 17;
+
+  // Information about extensions that are installed, masked to provide better
+  // privacy.  Only extensions from a single profile are reported; this will
+  // generally be the profile used when the browser is started.  The profile
+  // reported on will remain consistent at least until the browser is
+  // relaunched (or the profile is deleted by the user).
+  //
+  // Each client first picks a value for client_key derived from its UMA
+  // client_id:
+  //   client_key = client_id % 4096
+  // Then, each installed extension is mapped into a hash bucket according to
+  //   bucket = CityHash64(StringPrintf("%d:%s",
+  //                                    client_key, extension_id)) % 1024
+  // The client reports the set of hash buckets occupied by all installed
+  // extensions.  If multiple extensions map to the same bucket, that bucket is
+  // still only reported once.
+  repeated int32 occupied_extension_bucket = 18;
+
+  // The state of loaded extensions for this system. The system can have either
+  // no applicable extensions, extensions only from the webstore and verified by
+  // the webstore, extensions only from the webstore but not verified, or
+  // extensions not from the store. If there is a single off-store extension,
+  // then HAS_OFFSTORE is reported. This should be kept in sync with the
+  // corresponding enum in chrome/browser/metrics/extensions_metrics_provider.cc
+  enum ExtensionsState {
+    NO_EXTENSIONS = 0;
+    NO_OFFSTORE_VERIFIED = 1;
+    NO_OFFSTORE_UNVERIFIED = 2;
+    HAS_OFFSTORE = 3;
+  }
+  optional ExtensionsState offstore_extensions_state = 19;
+}
diff --git a/metricsd/uploader/proto/user_action_event.proto b/metricsd/uploader/proto/user_action_event.proto
new file mode 100644
index 000000000..30a93180d
--- /dev/null
+++ b/metricsd/uploader/proto/user_action_event.proto
@@ -0,0 +1,23 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Stores information about an event that occurs in response to a user action,
+// e.g. an interaction with a browser UI element.
+
+syntax = "proto2";
+
+option optimize_for = LITE_RUNTIME;
+option java_outer_classname = "UserActionEventProtos";
+option java_package = "org.chromium.components.metrics";
+
+package metrics;
+
+// Next tag: 3
+message UserActionEventProto {
+  // The name of the action, hashed.
+  optional fixed64 name_hash = 1;
+
+  // The timestamp for the event, in seconds since the epoch.
+  optional int64 time = 2;
+}
diff --git a/metricsd/uploader/sender.h b/metricsd/uploader/sender.h
new file mode 100644
index 000000000..521183407
--- /dev/null
+++ b/metricsd/uploader/sender.h
@@ -0,0 +1,18 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_UPLOADER_SENDER_H_
+#define METRICS_UPLOADER_SENDER_H_
+
+#include <string>
+
+// Abstract class for a Sender that uploads a metrics message.
+class Sender {
+ public:
+  virtual ~Sender() {}
+  // Sends a message |content| with its sha1 hash |hash|
+  virtual bool Send(const std::string& content, const std::string& hash) = 0;
+};
+
+#endif  // METRICS_UPLOADER_SENDER_H_
diff --git a/metricsd/uploader/sender_http.cc b/metricsd/uploader/sender_http.cc
new file mode 100644
index 000000000..a740310e8
--- /dev/null
+++ b/metricsd/uploader/sender_http.cc
@@ -0,0 +1,38 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "uploader/sender_http.h"
+
+#include <string>
+
+#include <base/logging.h>
+#include <base/strings/string_number_conversions.h>
+#include <chromeos/http/http_utils.h>
+#include <chromeos/mime_utils.h>
+
+HttpSender::HttpSender(const std::string server_url)
+    : server_url_(server_url) {}
+
+bool HttpSender::Send(const std::string& content,
+                      const std::string& content_hash) {
+  const std::string hash =
+      base::HexEncode(content_hash.data(), content_hash.size());
+
+  chromeos::http::HeaderList headers = {{"X-Chrome-UMA-Log-SHA1", hash}};
+  chromeos::ErrorPtr error;
+  auto response = chromeos::http::PostTextAndBlock(
+      server_url_,
+      content,
+      chromeos::mime::application::kWwwFormUrlEncoded,
+      headers,
+      chromeos::http::Transport::CreateDefault(),
+      &error);
+  if (!response || response->ExtractDataAsString() != "OK") {
+    if (error) {
+      DLOG(ERROR) << "Failed to send data: " << error->GetMessage();
+    }
+    return false;
+  }
+  return true;
+}
diff --git a/metricsd/uploader/sender_http.h b/metricsd/uploader/sender_http.h
new file mode 100644
index 000000000..380cad867
--- /dev/null
+++ b/metricsd/uploader/sender_http.h
@@ -0,0 +1,29 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_UPLOADER_SENDER_HTTP_H_
+#define METRICS_UPLOADER_SENDER_HTTP_H_
+
+#include <string>
+
+#include <base/macros.h>
+
+#include "uploader/sender.h"
+
+// Sender implemented using http_utils from libchromeos
+class HttpSender : public Sender {
+ public:
+  explicit HttpSender(std::string server_url);
+  ~HttpSender() override = default;
+  // Sends |content| whose SHA1 hash is |hash| to server_url with a synchronous
+  // POST request to server_url.
+  bool Send(const std::string& content, const std::string& hash) override;
+
+ private:
+  const std::string server_url_;
+
+  DISALLOW_COPY_AND_ASSIGN(HttpSender);
+};
+
+#endif  // METRICS_UPLOADER_SENDER_HTTP_H_
diff --git a/metricsd/uploader/system_profile_cache.cc b/metricsd/uploader/system_profile_cache.cc
new file mode 100644
index 000000000..adbe0ae0a
--- /dev/null
+++ b/metricsd/uploader/system_profile_cache.cc
@@ -0,0 +1,152 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "uploader/system_profile_cache.h"
+
+#include <base/files/file_util.h>
+#include <base/guid.h>
+#include <base/logging.h>
+#include <base/strings/string_number_conversions.h>
+#include <base/strings/string_util.h>
+#include <base/sys_info.h>
+#include <string>
+#include <vector>
+
+#include "constants.h"
+#include "persistent_integer.h"
+#include "uploader/metrics_log_base.h"
+#include "uploader/proto/chrome_user_metrics_extension.pb.h"
+
+namespace {
+
+const char kPersistentSessionIdFilename[] = "Sysinfo.SessionId";
+
+}  // namespace
+
+std::string ChannelToString(
+    const metrics::SystemProfileProto_Channel& channel) {
+  switch (channel) {
+    case metrics::SystemProfileProto::CHANNEL_STABLE:
+    return "STABLE";
+  case metrics::SystemProfileProto::CHANNEL_DEV:
+    return "DEV";
+  case metrics::SystemProfileProto::CHANNEL_BETA:
+    return "BETA";
+  case metrics::SystemProfileProto::CHANNEL_CANARY:
+    return "CANARY";
+  default:
+    return "UNKNOWN";
+  }
+}
+
+SystemProfileCache::SystemProfileCache()
+    : initialized_(false),
+    testing_(false),
+    config_root_("/"),
+    session_id_(new chromeos_metrics::PersistentInteger(
+        kPersistentSessionIdFilename)) {
+}
+
+SystemProfileCache::SystemProfileCache(bool testing,
+                                       const std::string& config_root)
+    : initialized_(false),
+      testing_(testing),
+      config_root_(config_root),
+      session_id_(new chromeos_metrics::PersistentInteger(
+          kPersistentSessionIdFilename)) {
+}
+
+bool SystemProfileCache::Initialize() {
+  CHECK(!initialized_)
+      << "this should be called only once in the metrics_daemon lifetime.";
+
+  if (!base::SysInfo::GetLsbReleaseValue("BRILLO_BUILD_TARGET_ID",
+                                         &profile_.build_target_id)) {
+    LOG(ERROR) << "Could not initialize system profile.";
+    return false;
+  }
+
+  std::string channel;
+  if (!base::SysInfo::GetLsbReleaseValue("BRILLO_CHANNEL", &channel) ||
+      !base::SysInfo::GetLsbReleaseValue("BRILLO_VERSION", &profile_.version)) {
+    // If the channel or version is missing, the image is not official.
+    // In this case, set the channel to unknown and the version to 0.0.0.0 to
+    // avoid polluting the production data.
+    channel = "";
+    profile_.version = metrics::kDefaultVersion;
+
+  }
+  profile_.client_id =
+      testing_ ? "client_id_test" :
+      GetPersistentGUID(metrics::kMetricsGUIDFilePath);
+  profile_.hardware_class = "unknown";
+  profile_.channel = ProtoChannelFromString(channel);
+
+  // Increment the session_id everytime we initialize this. If metrics_daemon
+  // does not crash, this should correspond to the number of reboots of the
+  // system.
+  session_id_->Add(1);
+  profile_.session_id = static_cast<int32_t>(session_id_->Get());
+
+  initialized_ = true;
+  return initialized_;
+}
+
+bool SystemProfileCache::InitializeOrCheck() {
+  return initialized_ || Initialize();
+}
+
+void SystemProfileCache::Populate(
+    metrics::ChromeUserMetricsExtension* metrics_proto) {
+  CHECK(metrics_proto);
+  CHECK(InitializeOrCheck())
+      << "failed to initialize system information.";
+
+  // The client id is hashed before being sent.
+  metrics_proto->set_client_id(
+      metrics::MetricsLogBase::Hash(profile_.client_id));
+  metrics_proto->set_session_id(profile_.session_id);
+
+  // Sets the product id.
+  metrics_proto->set_product(9);
+
+  metrics::SystemProfileProto* profile_proto =
+      metrics_proto->mutable_system_profile();
+  profile_proto->mutable_hardware()->set_hardware_class(
+      profile_.hardware_class);
+  profile_proto->set_app_version(profile_.version);
+  profile_proto->set_channel(profile_.channel);
+  metrics::SystemProfileProto_BrilloDeviceData* device_data =
+      profile_proto->mutable_brillo();
+  device_data->set_build_target_id(profile_.build_target_id);
+}
+
+std::string SystemProfileCache::GetPersistentGUID(
+    const std::string& filename) {
+  std::string guid;
+  base::FilePath filepath(filename);
+  if (!base::ReadFileToString(filepath, &guid)) {
+    guid = base::GenerateGUID();
+    // If we can't read or write the file, the guid will not be preserved during
+    // the next reboot. Crash.
+    CHECK(base::WriteFile(filepath, guid.c_str(), guid.size()));
+  }
+  return guid;
+}
+
+metrics::SystemProfileProto_Channel SystemProfileCache::ProtoChannelFromString(
+    const std::string& channel) {
+  if (channel == "stable") {
+    return metrics::SystemProfileProto::CHANNEL_STABLE;
+  } else if (channel == "dev") {
+    return metrics::SystemProfileProto::CHANNEL_DEV;
+  } else if (channel == "beta") {
+    return metrics::SystemProfileProto::CHANNEL_BETA;
+  } else if (channel == "canary") {
+    return metrics::SystemProfileProto::CHANNEL_CANARY;
+  }
+
+  DLOG(INFO) << "unknown channel: " << channel;
+  return metrics::SystemProfileProto::CHANNEL_UNKNOWN;
+}
diff --git a/metricsd/uploader/system_profile_cache.h b/metricsd/uploader/system_profile_cache.h
new file mode 100644
index 000000000..b6ff3377c
--- /dev/null
+++ b/metricsd/uploader/system_profile_cache.h
@@ -0,0 +1,73 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_UPLOADER_SYSTEM_PROFILE_CACHE_H_
+#define METRICS_UPLOADER_SYSTEM_PROFILE_CACHE_H_
+
+#include <stdint.h>
+
+#include <string>
+
+#include "base/compiler_specific.h"
+#include "base/gtest_prod_util.h"
+#include "base/memory/scoped_ptr.h"
+#include "persistent_integer.h"
+#include "uploader/proto/system_profile.pb.h"
+#include "uploader/system_profile_setter.h"
+
+namespace metrics {
+class ChromeUserMetricsExtension;
+}
+
+struct SystemProfile {
+  std::string version;
+  std::string hardware_class;
+  std::string client_id;
+  int session_id;
+  metrics::SystemProfileProto::Channel channel;
+  std::string build_target_id;
+};
+
+// Retrieves general system informations needed by the protobuf for context and
+// remembers them to avoid expensive calls.
+//
+// The cache is populated lazily. The only method needed is Populate.
+class SystemProfileCache : public SystemProfileSetter {
+ public:
+  SystemProfileCache();
+
+  SystemProfileCache(bool testing, const std::string& config_root);
+
+  // Populates the ProfileSystem protobuf with system information.
+  void Populate(metrics::ChromeUserMetricsExtension* metrics_proto) override;
+
+  // Converts a string representation of the channel to a
+  // SystemProfileProto_Channel
+  static metrics::SystemProfileProto_Channel ProtoChannelFromString(
+      const std::string& channel);
+
+  // Gets the persistent GUID and create it if it has not been created yet.
+  static std::string GetPersistentGUID(const std::string& filename);
+
+ private:
+  friend class UploadServiceTest;
+  FRIEND_TEST(UploadServiceTest, ExtractChannelFromDescription);
+  FRIEND_TEST(UploadServiceTest, ReadKeyValueFromFile);
+  FRIEND_TEST(UploadServiceTest, SessionIdIncrementedAtInitialization);
+  FRIEND_TEST(UploadServiceTest, ValuesInConfigFileAreSent);
+
+  // Fetches all informations and populates |profile_|
+  bool Initialize();
+
+  // Initializes |profile_| only if it has not been yet initialized.
+  bool InitializeOrCheck();
+
+  bool initialized_;
+  bool testing_;
+  std::string config_root_;
+  scoped_ptr<chromeos_metrics::PersistentInteger> session_id_;
+  SystemProfile profile_;
+};
+
+#endif  // METRICS_UPLOADER_SYSTEM_PROFILE_CACHE_H_
diff --git a/metricsd/uploader/system_profile_setter.h b/metricsd/uploader/system_profile_setter.h
new file mode 100644
index 000000000..c535664a0
--- /dev/null
+++ b/metricsd/uploader/system_profile_setter.h
@@ -0,0 +1,21 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_UPLOADER_SYSTEM_PROFILE_SETTER_H_
+#define METRICS_UPLOADER_SYSTEM_PROFILE_SETTER_H_
+
+namespace metrics {
+class ChromeUserMetricsExtension;
+}
+
+// Abstract class used to delegate populating SystemProfileProto with system
+// information to simplify testing.
+class SystemProfileSetter {
+ public:
+  virtual ~SystemProfileSetter() {}
+  // Populates the protobuf with system informations.
+  virtual void Populate(metrics::ChromeUserMetricsExtension* profile_proto) = 0;
+};
+
+#endif  // METRICS_UPLOADER_SYSTEM_PROFILE_SETTER_H_
diff --git a/metricsd/uploader/upload_service.cc b/metricsd/uploader/upload_service.cc
new file mode 100644
index 000000000..34110045a
--- /dev/null
+++ b/metricsd/uploader/upload_service.cc
@@ -0,0 +1,224 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "uploader/upload_service.h"
+
+#include <string>
+
+#include <base/bind.h>
+#include <base/logging.h>
+#include <base/memory/scoped_vector.h>
+#include <base/message_loop/message_loop.h>
+#include <base/metrics/histogram.h>
+#include <base/metrics/histogram_base.h>
+#include <base/metrics/histogram_snapshot_manager.h>
+#include <base/metrics/sparse_histogram.h>
+#include <base/metrics/statistics_recorder.h>
+#include <base/sha1.h>
+
+#include "serialization/metric_sample.h"
+#include "serialization/serialization_utils.h"
+#include "uploader/metrics_log.h"
+#include "uploader/sender_http.h"
+#include "uploader/system_profile_setter.h"
+
+const int UploadService::kMaxFailedUpload = 10;
+
+UploadService::UploadService(SystemProfileSetter* setter,
+                             MetricsLibraryInterface* metrics_lib,
+                             const std::string& server)
+    : system_profile_setter_(setter),
+      metrics_lib_(metrics_lib),
+      histogram_snapshot_manager_(this),
+      sender_(new HttpSender(server)),
+      testing_(false) {
+}
+
+UploadService::UploadService(SystemProfileSetter* setter,
+                             MetricsLibraryInterface* metrics_lib,
+                             const std::string& server,
+                             bool testing)
+    : UploadService(setter, metrics_lib, server) {
+  testing_ = testing;
+}
+
+void UploadService::Init(const base::TimeDelta& upload_interval,
+                         const std::string& metrics_file) {
+  base::StatisticsRecorder::Initialize();
+  metrics_file_ = metrics_file;
+
+  if (!testing_) {
+    base::MessageLoop::current()->PostDelayedTask(FROM_HERE,
+        base::Bind(&UploadService::UploadEventCallback,
+                   base::Unretained(this),
+                   upload_interval),
+        upload_interval);
+  }
+}
+
+void UploadService::StartNewLog() {
+  CHECK(!staged_log_) << "the staged log should be discarded before starting "
+                         "a new metrics log";
+  MetricsLog* log = new MetricsLog();
+  log->PopulateSystemProfile(system_profile_setter_.get());
+  current_log_.reset(log);
+}
+
+void UploadService::UploadEventCallback(const base::TimeDelta& interval) {
+  UploadEvent();
+
+  base::MessageLoop::current()->PostDelayedTask(FROM_HERE,
+      base::Bind(&UploadService::UploadEventCallback,
+                 base::Unretained(this),
+                 interval),
+      interval);
+}
+
+void UploadService::UploadEvent() {
+  if (staged_log_) {
+    // Previous upload failed, retry sending the logs.
+    SendStagedLog();
+    return;
+  }
+
+  // Previous upload successful, reading metrics sample from the file.
+  ReadMetrics();
+  GatherHistograms();
+
+  // No samples found. Exit to avoid sending an empty log.
+  if (!current_log_)
+    return;
+
+  StageCurrentLog();
+  SendStagedLog();
+}
+
+void UploadService::SendStagedLog() {
+  CHECK(staged_log_) << "staged_log_ must exist to be sent";
+
+  // If metrics are not enabled, discard the log and exit.
+  if (!metrics_lib_->AreMetricsEnabled()) {
+    LOG(INFO) << "Metrics disabled. Don't upload metrics samples.";
+    staged_log_.reset();
+    return;
+  }
+
+  std::string log_text;
+  staged_log_->GetEncodedLog(&log_text);
+  if (!sender_->Send(log_text, base::SHA1HashString(log_text))) {
+    ++failed_upload_count_;
+    if (failed_upload_count_ <= kMaxFailedUpload) {
+      LOG(WARNING) << "log upload failed " << failed_upload_count_
+                   << " times. It will be retried later.";
+      return;
+    }
+    LOG(WARNING) << "log failed more than " << kMaxFailedUpload << " times.";
+  } else {
+    LOG(INFO) << "uploaded " << log_text.length() << " bytes";
+  }
+  // Discard staged log.
+  staged_log_.reset();
+}
+
+void UploadService::Reset() {
+  staged_log_.reset();
+  current_log_.reset();
+  failed_upload_count_ = 0;
+}
+
+void UploadService::ReadMetrics() {
+  CHECK(!staged_log_)
+      << "cannot read metrics until the old logs have been discarded";
+
+  ScopedVector<metrics::MetricSample> vector;
+  metrics::SerializationUtils::ReadAndTruncateMetricsFromFile(
+      metrics_file_, &vector);
+
+  int i = 0;
+  for (ScopedVector<metrics::MetricSample>::iterator it = vector.begin();
+       it != vector.end(); it++) {
+    metrics::MetricSample* sample = *it;
+    AddSample(*sample);
+    i++;
+  }
+  DLOG(INFO) << i << " samples read";
+}
+
+void UploadService::AddSample(const metrics::MetricSample& sample) {
+  base::HistogramBase* counter;
+  switch (sample.type()) {
+    case metrics::MetricSample::CRASH:
+      AddCrash(sample.name());
+      break;
+    case metrics::MetricSample::HISTOGRAM:
+      counter = base::Histogram::FactoryGet(
+          sample.name(), sample.min(), sample.max(), sample.bucket_count(),
+          base::Histogram::kUmaTargetedHistogramFlag);
+      counter->Add(sample.sample());
+      break;
+    case metrics::MetricSample::SPARSE_HISTOGRAM:
+      counter = base::SparseHistogram::FactoryGet(
+          sample.name(), base::HistogramBase::kUmaTargetedHistogramFlag);
+      counter->Add(sample.sample());
+      break;
+    case metrics::MetricSample::LINEAR_HISTOGRAM:
+      counter = base::LinearHistogram::FactoryGet(
+          sample.name(),
+          1,
+          sample.max(),
+          sample.max() + 1,
+          base::Histogram::kUmaTargetedHistogramFlag);
+      counter->Add(sample.sample());
+      break;
+    case metrics::MetricSample::USER_ACTION:
+      GetOrCreateCurrentLog()->RecordUserAction(sample.name());
+      break;
+    default:
+      break;
+  }
+}
+
+void UploadService::AddCrash(const std::string& crash_name) {
+  if (crash_name == "user") {
+    GetOrCreateCurrentLog()->IncrementUserCrashCount();
+  } else if (crash_name == "kernel") {
+    GetOrCreateCurrentLog()->IncrementKernelCrashCount();
+  } else if (crash_name == "uncleanshutdown") {
+    GetOrCreateCurrentLog()->IncrementUncleanShutdownCount();
+  } else {
+    DLOG(ERROR) << "crash name unknown" << crash_name;
+  }
+}
+
+void UploadService::GatherHistograms() {
+  base::StatisticsRecorder::Histograms histograms;
+  base::StatisticsRecorder::GetHistograms(&histograms);
+
+  histogram_snapshot_manager_.PrepareDeltas(
+      base::Histogram::kNoFlags, base::Histogram::kUmaTargetedHistogramFlag);
+}
+
+void UploadService::RecordDelta(const base::HistogramBase& histogram,
+                                const base::HistogramSamples& snapshot) {
+  GetOrCreateCurrentLog()->RecordHistogramDelta(histogram.histogram_name(),
+                                                snapshot);
+}
+
+void UploadService::StageCurrentLog() {
+  CHECK(!staged_log_)
+      << "staged logs must be discarded before another log can be staged";
+
+  if (!current_log_) return;
+
+  staged_log_.swap(current_log_);
+  staged_log_->CloseLog();
+  failed_upload_count_ = 0;
+}
+
+MetricsLog* UploadService::GetOrCreateCurrentLog() {
+  if (!current_log_) {
+    StartNewLog();
+  }
+  return current_log_.get();
+}
diff --git a/metricsd/uploader/upload_service.h b/metricsd/uploader/upload_service.h
new file mode 100644
index 000000000..c08fc1ac8
--- /dev/null
+++ b/metricsd/uploader/upload_service.h
@@ -0,0 +1,153 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef METRICS_UPLOADER_UPLOAD_SERVICE_H_
+#define METRICS_UPLOADER_UPLOAD_SERVICE_H_
+
+#include <string>
+
+#include "base/metrics/histogram_base.h"
+#include "base/metrics/histogram_flattener.h"
+#include "base/metrics/histogram_snapshot_manager.h"
+
+#include "metrics/metrics_library.h"
+#include "uploader/metrics_log.h"
+#include "uploader/sender.h"
+#include "uploader/system_profile_cache.h"
+
+namespace metrics {
+class ChromeUserMetricsExtension;
+class CrashSample;
+class HistogramSample;
+class LinearHistogramSample;
+class MetricSample;
+class SparseHistogramSample;
+class UserActionSample;
+}
+
+class SystemProfileSetter;
+
+// Service responsible for uploading the metrics periodically to the server.
+// This service works as a simple 2-state state-machine.
+//
+// The two states are the presence or not of a staged log.
+// A staged log is a compressed protobuffer containing both the aggregated
+// metrics and event and information about the client. (product, hardware id,
+// etc...).
+//
+// At regular intervals, the upload event will be triggered and the following
+// will happen:
+// * if a staged log is present:
+//    The previous upload may have failed for various reason. We then retry to
+//    upload the same log.
+//    - if the upload is successful, we discard the log (therefore
+//      transitioning back to no staged log)
+//    - if the upload fails, we keep the log to try again later.
+//    We do not try to read the metrics that are stored on
+//    the disk as we want to avoid storing the metrics in memory.
+//
+// * if no staged logs are present:
+//    Read all metrics from the disk, aggregate them and try to send them.
+//    - if the upload succeeds, we discard the staged log (transitioning back
+//      to the no staged log state)
+//    - if the upload fails, we keep the staged log in memory to retry
+//      uploading later.
+//
+class UploadService : public base::HistogramFlattener {
+ public:
+  explicit UploadService(SystemProfileSetter* setter,
+                         MetricsLibraryInterface* metrics_lib,
+                         const std::string& server);
+
+  void Init(const base::TimeDelta& upload_interval,
+            const std::string& metrics_file);
+
+  // Starts a new log. The log needs to be regenerated after each successful
+  // launch as it is destroyed when staging the log.
+  void StartNewLog();
+
+  // Event callback for handling MessageLoop events.
+  void UploadEventCallback(const base::TimeDelta& interval);
+
+  // Triggers an upload event.
+  void UploadEvent();
+
+  // Sends the staged log.
+  void SendStagedLog();
+
+  // Implements inconsistency detection to match HistogramFlattener's
+  // interface.
+  void InconsistencyDetected(
+      base::HistogramBase::Inconsistency problem) override {}
+  void UniqueInconsistencyDetected(
+      base::HistogramBase::Inconsistency problem) override {}
+  void InconsistencyDetectedInLoggedCount(int amount) override {}
+
+ private:
+  friend class UploadServiceTest;
+
+  FRIEND_TEST(UploadServiceTest, CanSendMultipleTimes);
+  FRIEND_TEST(UploadServiceTest, DiscardLogsAfterTooManyFailedUpload);
+  FRIEND_TEST(UploadServiceTest, EmptyLogsAreNotSent);
+  FRIEND_TEST(UploadServiceTest, FailedSendAreRetried);
+  FRIEND_TEST(UploadServiceTest, LogContainsAggregatedValues);
+  FRIEND_TEST(UploadServiceTest, LogEmptyAfterUpload);
+  FRIEND_TEST(UploadServiceTest, LogEmptyByDefault);
+  FRIEND_TEST(UploadServiceTest, LogKernelCrash);
+  FRIEND_TEST(UploadServiceTest, LogUncleanShutdown);
+  FRIEND_TEST(UploadServiceTest, LogUserCrash);
+  FRIEND_TEST(UploadServiceTest, UnknownCrashIgnored);
+  FRIEND_TEST(UploadServiceTest, ValuesInConfigFileAreSent);
+
+  // Private constructor for use in unit testing.
+  UploadService(SystemProfileSetter* setter,
+                MetricsLibraryInterface* metrics_lib,
+                const std::string& server,
+                bool testing);
+
+  // If a staged log fails to upload more than kMaxFailedUpload times, it
+  // will be discarded.
+  static const int kMaxFailedUpload;
+
+  // Resets the internal state.
+  void Reset();
+
+  // Reads all the metrics from the disk.
+  void ReadMetrics();
+
+  // Adds a generic sample to the current log.
+  void AddSample(const metrics::MetricSample& sample);
+
+  // Adds a crash to the current log.
+  void AddCrash(const std::string& crash_name);
+
+  // Aggregates all histogram available in memory and store them in the current
+  // log.
+  void GatherHistograms();
+
+  // Callback for HistogramSnapshotManager to store the histograms.
+  void RecordDelta(const base::HistogramBase& histogram,
+                   const base::HistogramSamples& snapshot) override;
+
+  // Compiles all the samples received into a single protobuf and adds all
+  // system information.
+  void StageCurrentLog();
+
+  // Returns the current log. If there is no current log, creates it first.
+  MetricsLog* GetOrCreateCurrentLog();
+
+  scoped_ptr<SystemProfileSetter> system_profile_setter_;
+  MetricsLibraryInterface* metrics_lib_;
+  base::HistogramSnapshotManager histogram_snapshot_manager_;
+  scoped_ptr<Sender> sender_;
+  int failed_upload_count_;
+  scoped_ptr<MetricsLog> current_log_;
+  scoped_ptr<MetricsLog> staged_log_;
+
+  std::string metrics_file_;
+
+  bool testing_;
+};
+
+#endif  // METRICS_UPLOADER_UPLOAD_SERVICE_H_
diff --git a/metricsd/uploader/upload_service_test.cc b/metricsd/uploader/upload_service_test.cc
new file mode 100644
index 000000000..efd0a56fa
--- /dev/null
+++ b/metricsd/uploader/upload_service_test.cc
@@ -0,0 +1,254 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <gtest/gtest.h>
+
+#include "base/at_exit.h"
+#include "base/files/file_util.h"
+#include "base/files/scoped_temp_dir.h"
+#include "base/logging.h"
+#include "base/sys_info.h"
+#include "metrics_library_mock.h"
+#include "serialization/metric_sample.h"
+#include "uploader/metrics_log.h"
+#include "uploader/mock/mock_system_profile_setter.h"
+#include "uploader/mock/sender_mock.h"
+#include "uploader/proto/chrome_user_metrics_extension.pb.h"
+#include "uploader/proto/histogram_event.pb.h"
+#include "uploader/proto/system_profile.pb.h"
+#include "uploader/system_profile_cache.h"
+#include "uploader/upload_service.h"
+
+class UploadServiceTest : public testing::Test {
+ protected:
+  UploadServiceTest()
+      : cache_(true, "/"),
+        upload_service_(new MockSystemProfileSetter(), &metrics_lib_,
+                        kMetricsServer, true),
+        exit_manager_(new base::AtExitManager()) {
+    sender_ = new SenderMock;
+    upload_service_.sender_.reset(sender_);
+    upload_service_.Init(base::TimeDelta::FromMinutes(30), kMetricsFilePath);
+  }
+
+  virtual void SetUp() {
+    CHECK(dir_.CreateUniqueTempDir());
+    upload_service_.GatherHistograms();
+    upload_service_.Reset();
+    sender_->Reset();
+
+    chromeos_metrics::PersistentInteger::SetTestingMode(true);
+    cache_.session_id_.reset(new chromeos_metrics::PersistentInteger(
+        dir_.path().Append("session_id").value()));
+  }
+
+  scoped_ptr<metrics::MetricSample> Crash(const std::string& name) {
+    return metrics::MetricSample::CrashSample(name);
+  }
+
+  base::ScopedTempDir dir_;
+  SenderMock* sender_;
+  SystemProfileCache cache_;
+  UploadService upload_service_;
+  MetricsLibraryMock metrics_lib_;
+
+  scoped_ptr<base::AtExitManager> exit_manager_;
+};
+
+// Tests that the right crash increments a values.
+TEST_F(UploadServiceTest, LogUserCrash) {
+  upload_service_.AddSample(*Crash("user").get());
+
+  MetricsLog* log = upload_service_.current_log_.get();
+  metrics::ChromeUserMetricsExtension* proto = log->uma_proto();
+
+  EXPECT_EQ(1, proto->system_profile().stability().other_user_crash_count());
+}
+
+TEST_F(UploadServiceTest, LogUncleanShutdown) {
+  upload_service_.AddSample(*Crash("uncleanshutdown"));
+
+  EXPECT_EQ(1, upload_service_.current_log_
+                   ->uma_proto()
+                   ->system_profile()
+                   .stability()
+                   .unclean_system_shutdown_count());
+}
+
+TEST_F(UploadServiceTest, LogKernelCrash) {
+  upload_service_.AddSample(*Crash("kernel"));
+
+  EXPECT_EQ(1, upload_service_.current_log_
+                   ->uma_proto()
+                   ->system_profile()
+                   .stability()
+                   .kernel_crash_count());
+}
+
+TEST_F(UploadServiceTest, UnknownCrashIgnored) {
+  upload_service_.AddSample(*Crash("foo"));
+
+  // The log should be empty.
+  EXPECT_FALSE(upload_service_.current_log_);
+}
+
+TEST_F(UploadServiceTest, FailedSendAreRetried) {
+  sender_->set_should_succeed(false);
+
+  upload_service_.AddSample(*Crash("user"));
+  upload_service_.UploadEvent();
+  EXPECT_EQ(1, sender_->send_call_count());
+  std::string sent_string = sender_->last_message();
+
+  upload_service_.UploadEvent();
+  EXPECT_EQ(2, sender_->send_call_count());
+  EXPECT_EQ(sent_string, sender_->last_message());
+}
+
+TEST_F(UploadServiceTest, DiscardLogsAfterTooManyFailedUpload) {
+  sender_->set_should_succeed(false);
+  upload_service_.AddSample(*Crash("user"));
+
+  for (int i = 0; i < UploadService::kMaxFailedUpload; i++) {
+    upload_service_.UploadEvent();
+  }
+
+  EXPECT_TRUE(upload_service_.staged_log_);
+  upload_service_.UploadEvent();
+  EXPECT_FALSE(upload_service_.staged_log_);
+}
+
+TEST_F(UploadServiceTest, EmptyLogsAreNotSent) {
+  upload_service_.UploadEvent();
+  EXPECT_FALSE(upload_service_.current_log_);
+  EXPECT_EQ(0, sender_->send_call_count());
+}
+
+TEST_F(UploadServiceTest, LogEmptyByDefault) {
+  UploadService upload_service(new MockSystemProfileSetter(), &metrics_lib_,
+                               kMetricsServer);
+
+  // current_log_ should be initialized later as it needs AtExitManager to exit
+  // in order to gather system information from SysInfo.
+  EXPECT_FALSE(upload_service.current_log_);
+}
+
+TEST_F(UploadServiceTest, CanSendMultipleTimes) {
+  upload_service_.AddSample(*Crash("user"));
+  upload_service_.UploadEvent();
+
+  std::string first_message = sender_->last_message();
+
+  upload_service_.AddSample(*Crash("kernel"));
+  upload_service_.UploadEvent();
+
+  EXPECT_NE(first_message, sender_->last_message());
+}
+
+TEST_F(UploadServiceTest, LogEmptyAfterUpload) {
+  upload_service_.AddSample(*Crash("user"));
+
+  EXPECT_TRUE(upload_service_.current_log_);
+
+  upload_service_.UploadEvent();
+  EXPECT_FALSE(upload_service_.current_log_);
+}
+
+TEST_F(UploadServiceTest, LogContainsAggregatedValues) {
+  scoped_ptr<metrics::MetricSample> histogram =
+      metrics::MetricSample::HistogramSample("foo", 10, 0, 42, 10);
+  upload_service_.AddSample(*histogram.get());
+
+
+  scoped_ptr<metrics::MetricSample> histogram2 =
+      metrics::MetricSample::HistogramSample("foo", 11, 0, 42, 10);
+  upload_service_.AddSample(*histogram2.get());
+
+  upload_service_.GatherHistograms();
+  metrics::ChromeUserMetricsExtension* proto =
+      upload_service_.current_log_->uma_proto();
+  EXPECT_EQ(1, proto->histogram_event().size());
+}
+
+TEST_F(UploadServiceTest, ExtractChannelFromString) {
+  EXPECT_EQ(
+      SystemProfileCache::ProtoChannelFromString(
+          "developer-build"),
+      metrics::SystemProfileProto::CHANNEL_UNKNOWN);
+
+  EXPECT_EQ(metrics::SystemProfileProto::CHANNEL_DEV,
+            SystemProfileCache::ProtoChannelFromString("dev-channel"));
+
+  EXPECT_EQ(metrics::SystemProfileProto::CHANNEL_UNKNOWN,
+            SystemProfileCache::ProtoChannelFromString("dev-channel test"));
+}
+
+TEST_F(UploadServiceTest, ValuesInConfigFileAreSent) {
+  std::string name("os name");
+  std::string content(
+      "CHROMEOS_RELEASE_NAME=" + name +
+      "\nCHROMEOS_RELEASE_VERSION=version\n"
+      "CHROMEOS_RELEASE_DESCRIPTION=description beta-channel test\n"
+      "CHROMEOS_RELEASE_TRACK=beta-channel\n"
+      "CHROMEOS_RELEASE_BUILD_TYPE=developer build\n"
+      "CHROMEOS_RELEASE_BOARD=myboard");
+
+  base::SysInfo::SetChromeOSVersionInfoForTest(content, base::Time());
+  scoped_ptr<metrics::MetricSample> histogram =
+      metrics::MetricSample::SparseHistogramSample("myhistogram", 1);
+  SystemProfileCache* local_cache_ = new SystemProfileCache(true, "/");
+  local_cache_->session_id_.reset(new chromeos_metrics::PersistentInteger(
+        dir_.path().Append("session_id").value()));
+
+  upload_service_.system_profile_setter_.reset(local_cache_);
+  // Reset to create the new log with the profile setter.
+  upload_service_.Reset();
+  upload_service_.AddSample(*histogram.get());
+  upload_service_.UploadEvent();
+
+  EXPECT_EQ(1, sender_->send_call_count());
+  EXPECT_TRUE(sender_->is_good_proto());
+  EXPECT_EQ(1, sender_->last_message_proto().histogram_event().size());
+
+  EXPECT_EQ(name, sender_->last_message_proto().system_profile().os().name());
+  EXPECT_EQ(metrics::SystemProfileProto::CHANNEL_BETA,
+            sender_->last_message_proto().system_profile().channel());
+  EXPECT_NE(0, sender_->last_message_proto().client_id());
+  EXPECT_NE(0,
+            sender_->last_message_proto().system_profile().build_timestamp());
+  EXPECT_NE(0, sender_->last_message_proto().session_id());
+}
+
+TEST_F(UploadServiceTest, PersistentGUID) {
+  std::string tmp_file = dir_.path().Append("tmpfile").value();
+
+  std::string first_guid = SystemProfileCache::GetPersistentGUID(tmp_file);
+  std::string second_guid = SystemProfileCache::GetPersistentGUID(tmp_file);
+
+  // The GUID are cached.
+  EXPECT_EQ(first_guid, second_guid);
+
+  base::DeleteFile(base::FilePath(tmp_file), false);
+
+  first_guid = SystemProfileCache::GetPersistentGUID(tmp_file);
+  base::DeleteFile(base::FilePath(tmp_file), false);
+  second_guid = SystemProfileCache::GetPersistentGUID(tmp_file);
+
+  // Random GUIDs are generated (not all the same).
+  EXPECT_NE(first_guid, second_guid);
+}
+
+TEST_F(UploadServiceTest, SessionIdIncrementedAtInitialization) {
+  cache_.Initialize();
+  int session_id = cache_.profile_.session_id;
+  cache_.initialized_ = false;
+  cache_.Initialize();
+  EXPECT_EQ(cache_.profile_.session_id, session_id + 1);
+}
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+
+  return RUN_ALL_TESTS();
+}