libchromeos: Add GetDefaultCompletionAction() to AsyncEventSequencer

In many cases the async callback from DBusObject::RegisterAsync()
should do nothing. So, rather than providing a dummy method every
time this is the case, provide a helper on AsyncEventSequencer
class to provide the default (NO-OP) CompletionAction callback.

BUG=None
TEST=FEATURES=test emerge-link libchromeos

Change-Id: Ie17295a32b609254d52adc979ba5fc11b44f4d31
Reviewed-on: https://chromium-review.googlesource.com/216293
Reviewed-by: Christopher Wiley <wiley@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
Tested-by: Alex Vakulenko <avakulenko@chromium.org>

5 files changed, 14 insertions, 10 deletions

diff --git a/chromeos/dbus/async_event_sequencer.cc b/chromeos/dbus/async_event_sequencer.cc
index 33cf9ce..0f9c455 100644
--- a/chromeos/dbus/async_event_sequencer.cc
+++ b/chromeos/dbus/async_event_sequencer.cc
@@ -43,6 +43,7 @@ void AsyncEventSequencer::OnAllTasksCompletedCall(
 namespace {
 void IgnoreSuccess(const AsyncEventSequencer::CompletionTask& task,
                    bool /*success*/) { task.Run(); }
+void DoNothing(bool success) {}
 }  // namespace
 
 AsyncEventSequencer::CompletionAction AsyncEventSequencer::WrapCompletionTask(
@@ -50,6 +51,11 @@ AsyncEventSequencer::CompletionAction AsyncEventSequencer::WrapCompletionTask(
   return base::Bind(&IgnoreSuccess, task);
 }
 
+AsyncEventSequencer::CompletionAction
+    AsyncEventSequencer::GetDefaultCompletionAction() {
+  return base::Bind(&DoNothing);
+}
+
 void AsyncEventSequencer::HandleFinish(int registration_number,
                                        const std::string& error_message,
                                        bool failure_is_fatal, bool success) {
diff --git a/chromeos/dbus/async_event_sequencer.h b/chromeos/dbus/async_event_sequencer.h
index ee10f28..38e193e 100644
--- a/chromeos/dbus/async_event_sequencer.h
+++ b/chromeos/dbus/async_event_sequencer.h
@@ -67,7 +67,9 @@ class CHROMEOS_EXPORT AsyncEventSequencer
 
   // Wrap a CompletionTask with a function that discards the result.
   // This CompletionTask retains no references to the AsyncEventSequencer.
-  CompletionAction WrapCompletionTask(const CompletionTask& task);
+  static CompletionAction WrapCompletionTask(const CompletionTask& task);
+  // Create a default CompletionAction that doesn't do anything when called.
+  static CompletionAction GetDefaultCompletionAction();
 
  private:
   // We'll partially bind this function before giving it back via
diff --git a/chromeos/dbus/dbus_object_unittest.cc b/chromeos/dbus/dbus_object_unittest.cc
index f9835ae..ba66e58 100644
--- a/chromeos/dbus/dbus_object_unittest.cc
+++ b/chromeos/dbus/dbus_object_unittest.cc
@@ -34,8 +34,6 @@ const char kTestMethod_StrLen[] = "StrLen";
 const char kTestInterface3[] = "org.chromium.Test.NoOpInterface";
 const char kTestMethod_NoOp[] = "NoOp";
 
-void NoAction(bool all_succeeded) {}
-
 struct Calc {
   int Add(ErrorPtr* error, int x, int y) { return x + y; }
   int Negate(ErrorPtr* error, int x) { return -x; }
@@ -90,7 +88,8 @@ class DBusObjectTest : public ::testing::Test {
     base::Callback<void(ErrorPtr*)> noop_callback = base::Bind(NoOp);
     itf3->AddMethodHandler(kTestMethod_NoOp, noop_callback);
 
-    dbus_object_->RegisterAsync(base::Bind(NoAction));
+    dbus_object_->RegisterAsync(
+        AsyncEventSequencer::GetDefaultCompletionAction());
   }
 
   void ExpectError(dbus::Response* response, const std::string& expected_code) {
diff --git a/chromeos/dbus/exported_object_manager_unittest.cc b/chromeos/dbus/exported_object_manager_unittest.cc
index 32ecb37..57152fa 100644
--- a/chromeos/dbus/exported_object_manager_unittest.cc
+++ b/chromeos/dbus/exported_object_manager_unittest.cc
@@ -94,8 +94,6 @@ void VerifyInterfaceDropSignal(dbus::Signal* signal) {
   EXPECT_EQ(path, kClaimedTestPath);
 }
 
-void NoAction(bool all_succeeded) {}
-
 }  // namespace
 
 class ExportedObjectManagerTest: public ::testing::Test {
@@ -116,7 +114,7 @@ class ExportedObjectManagerTest: public ::testing::Test {
                 ExportMethod(_, _, _, _)).Times(AnyNumber());
     om_.reset(new ExportedObjectManager(bus_.get(), kTestPath));
     property_writer_ = base::Bind(&WriteTestPropertyDict);
-    om_->RegisterAsync(base::Bind(NoAction));
+    om_->RegisterAsync(AsyncEventSequencer::GetDefaultCompletionAction());
   }
 
   void TearDown() override {
diff --git a/chromeos/dbus/exported_property_set_unittest.cc b/chromeos/dbus/exported_property_set_unittest.cc
index 330cfce..eda6098 100644
--- a/chromeos/dbus/exported_property_set_unittest.cc
+++ b/chromeos/dbus/exported_property_set_unittest.cc
@@ -53,8 +53,6 @@ const dbus::ObjectPath kMethodsExportedOnPath(std::string("/export"));
 const dbus::ObjectPath kTestObjectPathInit(std::string("/path_init"));
 const dbus::ObjectPath kTestObjectPathUpdate(std::string("/path_update"));
 
-void NoAction(bool all_succeeded) {}
-
 }  // namespace
 
 class ExportedPropertySetTest : public ::testing::Test {
@@ -99,7 +97,8 @@ class ExportedPropertySetTest : public ::testing::Test {
       itf3->AddProperty(kStringListPropName, &stringlist_prop_);
       itf3->AddProperty(kPathListPropName, &pathlist_prop_);
       itf3->AddProperty(kUint8ListPropName, &uint8list_prop_);
-      dbus_object_.RegisterAsync(base::Bind(NoAction));
+      dbus_object_.RegisterAsync(
+          AsyncEventSequencer::GetDefaultCompletionAction());
     }
     virtual ~Properties() {}