Improve browser startup time

A number of optimizations are made to improve the time to interact with the UI quicker.
Steps are made to parallelize the web engine initialization while others removed
impediments to the UI bring up.

Changes:
- Engine Initialization is moved to an async task.
- A new NoShow BrowserLauncher activity is added to chain-load BrowserActivity at startup
   obviating the blank white screen shown.
- Native libraries are loaded asynchronously in a background thread.
- ResourceExtractor is started much earlier than before.
- BrowserSettings is synced to native only after engine initialization.
- Other parts of UI are made aware of engine initialization state to throttle actions.

Change-Id: Icd4959769fa9813170baf7023c46b696b30dfed1

1 files changed, 18 insertions, 2 deletions

diff --git a/src/com/android/browser/BrowserSettings.java b/src/com/android/browser/BrowserSettings.java
index b9588542..255aaf82 100644
--- a/src/com/android/browser/BrowserSettings.java
+++ b/src/com/android/browser/BrowserSettings.java
@@ -130,6 +130,9 @@ public class BrowserSettings implements OnSharedPreferenceChangeListener,
 
     private static String sFactoryResetUrl;
 
+    private boolean mEngineInitialized = false;
+    private boolean mSyncManagedSettings = false;
+
     public static synchronized void initialize(final Context context) {
         if (sInstance == null)
             sInstance = new BrowserSettings(context);
@@ -142,7 +145,6 @@ public class BrowserSettings implements OnSharedPreferenceChangeListener,
     private BrowserSettings(Context context) {
         mContext = context.getApplicationContext();
         mPrefs = PreferenceManager.getDefaultSharedPreferences(mContext);
-        mAutofillHandler = new AutofillHandler(mContext);
         mManagedSettings = new LinkedList<WeakReference<WebSettings>>();
         mCustomUserAgents = new WeakHashMap<WebSettings, String>();
         BackgroundHandler.execute(mSetup);
@@ -150,7 +152,16 @@ public class BrowserSettings implements OnSharedPreferenceChangeListener,
 
     public void setController(Controller controller) {
         mController = controller;
-        if (sInitialized) {
+        mNeedsSharedSync = true;
+    }
+
+    public void onEngineInitializationComplete() {
+        mEngineInitialized = true;
+        mAutofillHandler = new AutofillHandler(mContext);
+        if (mSyncManagedSettings) {
+            syncManagedSettings();
+        }
+        if (mNeedsSharedSync) {
             syncSharedSettings();
         }
     }
@@ -402,6 +413,11 @@ public class BrowserSettings implements OnSharedPreferenceChangeListener,
     }
 
     private void syncManagedSettings() {
+        if (!mEngineInitialized) {
+            mSyncManagedSettings = true;
+            return;
+        }
+        mSyncManagedSettings = false;
         syncSharedSettings();
         synchronized (mManagedSettings) {
             Iterator<WeakReference<WebSettings>> iter = mManagedSettings.iterator();