Separate deferred startup into tasks.

chrome/android/java/src/org/chromium/chrome/browser/tab/TabWebContentsObserver.java

 // Copyright 2015 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.
 
 package org.chromium.chrome.browser.tab;
 
 import android.os.SystemClock;
 import android.support.annotation.IntDef;
 import android.view.View;
 
@@ skipping 189 matching lines @@
             int transitionType) {
         if (isMainFrame && UmaUtils.isRunningApplicationStart()) {
             // Currently it takes about 2000ms to commit a navigation if the measurement
             // begins very early in the browser start. How many buckets (b) are needed to
             // explore the _typical_ values with granularity 100ms and a maximum duration
             // of 1 minute?
             //   s^{n+1} / s^{n} = 2100 / 2000
             //   s = 1.05
             //   s^b = 60000
             //   b = ln(60000) / ln(1.05) ~= 225
-            RecordHistogram.recordCustomTimesHistogram("Startup.FirstCommitNavigationTime",
-                    SystemClock.uptimeMillis() - UmaUtils.getMainEntryPointTime(),
+            RecordHistogram.recordCustomTimesHistogram("Startup.FirstCommitNavigationTime2",
+                    SystemClock.uptimeMillis() - UmaUtils.getForegroundStartTime(),
                     1, 60000 /* 1 minute */, TimeUnit.MILLISECONDS, 225);
             UmaUtils.setRunningApplicationStart(false);
         }
 
         if (isMainFrame) {
             mTab.setIsTabStateDirty(true);
             mTab.updateTitle();
         }
 
         RewindableIterator<TabObserver> observers = mTab.getTabObservers();
@@ skipping 89 matching lines @@
         }
     }
 
     @Override
     public void destroy() {
         MediaCaptureNotificationService.updateMediaNotificationForTab(
                 mTab.getApplicationContext(), mTab.getId(), false, false, mTab.getUrl());
         super.destroy();
     }
 }