Reland of Separate deferred startup into tasks.

chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java
index 229deff15cfccb787b2b3cec375b489803071936..b052938307e50d7adf4f85b135f131c5cf7cd8a3 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java
@@ -20,8 +20,6 @@ import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
-import android.os.Looper;
-import android.os.MessageQueue;
 import android.os.SystemClock;
 import android.support.v7.app.AlertDialog;
 import android.util.DisplayMetrics;
@@ -162,9 +160,6 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
      */
     static final int NO_CONTROL_CONTAINER = -1;
 
-    /** Delay in ms after first page load finishes before we initiate deferred startup actions. */
-    private static final int DEFERRED_STARTUP_DELAY_MS = 1000;
-
     private static final int RECORD_MULTI_WINDOW_SCREEN_WIDTH_DELAY_MS = 5000;
 
     /**
@@ -187,8 +182,7 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
 
     protected IntentHandler mIntentHandler;
 
-    /** Whether onDeferredStartup() has been run. */
-    private boolean mDeferredStartupNotified;
+    private boolean mDeferredStartupPosted;
 
     // The class cannot implement TouchExplorationStateChangeListener,
     // because it is only available for Build.VERSION_CODES.KITKAT and later.
@@ -221,7 +215,7 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
 
     // A set of views obscuring all tabs. When this set is nonempty,
     // all tab content will be hidden from the accessibility tree.
-    private List<View> mViewsObscuringAllTabs = new ArrayList<View>();
+    private List<View> mViewsObscuringAllTabs = new ArrayList<>();
 
     private static AppMenuHandlerFactory sAppMenuHandlerFactory = new AppMenuHandlerFactory() {
         @Override
@@ -694,38 +688,57 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
         return false;
     }
 
+    /**
+     * Overriding methods should queue tasks on the DeferredStartupHandler before or after calling
+     * super depending on whether the tasks should run before or after these ones.
+     */
     @Override
     protected void onDeferredStartup() {
         super.onDeferredStartup();
-        DeferredStartupHandler.getInstance().onDeferredStartupForApp();
-        onDeferredStartupForActivity();
+        initDeferredStartupForActivity();
+        DeferredStartupHandler.getInstance().initDeferredStartupForApp();
+        DeferredStartupHandler.getInstance().queueDeferredTasksOnIdleHandler();
     }
 
     /**
      * All deferred startup tasks that require the activity rather than the app should go here.
      */
-    private void onDeferredStartupForActivity() {
-        BeamController.registerForBeam(this, new BeamProvider() {
+    private void initDeferredStartupForActivity() {
+        DeferredStartupHandler.getInstance().addDeferredTask(new Runnable() {
             @Override
-            public String getTabUrlForBeam() {
-                if (isOverlayVisible()) return null;
-                if (getActivityTab() == null) return null;
-                return getActivityTab().getUrl();
+            public void run() {
+                if (isActivityDestroyed()) return;
+                BeamController.registerForBeam(ChromeActivity.this, new BeamProvider() {
+                    @Override
+                    public String getTabUrlForBeam() {
+                        if (isOverlayVisible()) return null;
+                        if (getActivityTab() == null) return null;
+                        return getActivityTab().getUrl();
+                    }
+                });
+
+                UpdateMenuItemHelper.getInstance().checkForUpdateOnBackgroundThread(
+                        ChromeActivity.this);
             }
         });
 
-        UpdateMenuItemHelper.getInstance().checkForUpdateOnBackgroundThread(this);
-
-        if (mToolbarManager != null) {
-            String simpleName = getClass().getSimpleName();
-            RecordHistogram.recordTimesHistogram("MobileStartup.ToolbarInflationTime." + simpleName,
-                    mInflateInitialLayoutDurationMs, TimeUnit.MILLISECONDS);
-            mToolbarManager.onDeferredStartup(getOnCreateTimestampMs(), simpleName);
-        }
+        DeferredStartupHandler.getInstance().addDeferredTask(new Runnable() {
+            @Override
+            public void run() {
+                if (isActivityDestroyed()) return;
+                if (mToolbarManager != null) {
+                    String simpleName = getClass().getSimpleName();
+                    RecordHistogram.recordTimesHistogram(
+                            "MobileStartup.ToolbarInflationTime." + simpleName,
+                            mInflateInitialLayoutDurationMs, TimeUnit.MILLISECONDS);
+                    mToolbarManager.onDeferredStartup(getOnCreateTimestampMs(), simpleName);
+                }
 
-        if (MultiWindowUtils.getInstance().isInMultiWindowMode(this)) {
-            onDeferredStartupForMultiWindowMode();
-        }
+                if (MultiWindowUtils.getInstance().isInMultiWindowMode(ChromeActivity.this)) {
+                    onDeferredStartupForMultiWindowMode();
+                }
+            }
+        });
     }
 
     /**
@@ -1655,29 +1668,13 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
     }
 
     protected final void postDeferredStartupIfNeeded() {
-        if (!mDeferredStartupNotified) {
+        if (!mDeferredStartupPosted) {
+            mDeferredStartupPosted = true;
             RecordHistogram.recordLongTimesHistogram(
-                    "UMA.Debug.EnableCrashUpload.PostDeferredStartUptime",
-                    SystemClock.uptimeMillis() - UmaUtils.getMainEntryPointTime(),
+                    "UMA.Debug.EnableCrashUpload.PostDeferredStartUptime2",
+                    SystemClock.uptimeMillis() - UmaUtils.getForegroundStartTime(),
                     TimeUnit.MILLISECONDS);
-
-            // We want to perform deferred startup tasks a short time after the first page
-            // load completes, but only when the main thread Looper has become idle.
-            mHandler.postDelayed(new Runnable() {
-                @Override
-                public void run() {
-                    if (!mDeferredStartupNotified && !isActivityDestroyed()) {
-                        mDeferredStartupNotified = true;
-                        Looper.myQueue().addIdleHandler(new MessageQueue.IdleHandler() {
-                            @Override
-                            public boolean queueIdle() {
-                                onDeferredStartup();
-                                return false;  // Remove this idle handler.
-                            }
-                        });
-                    }
-                }
-            }, DEFERRED_STARTUP_DELAY_MS);
+            onDeferredStartup();
         }
     }