[Android] Add phone progress bar animation behind a flag.

chrome/android/java/src/org/chromium/chrome/browser/toolbar/ToolbarLayout.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.toolbar;
 
 import android.annotation.SuppressLint;
 import android.content.Context;
 import android.graphics.Canvas;
 import android.graphics.Rect;
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             }
         });
         mAppMenuButtonHelper = appMenuButtonHelper;
     }
 
     /**
      *  This function handles native dependent initialization for this class
      */
     public void onNativeLibraryReady() {
         mNativeLibraryReady = true;
+        mProgressBar.initializeAnimation();
     }
 
     /**
      * @return The menu button view.
      */
     protected View getMenuButton() {
         return mMenuButton;
     }
 
     /**
@@ skipping 403 matching lines @@
     }
 
     /**
      * Opens hompage in the current tab.
      */
     protected void openHomepage() {
         getLocationBar().hideSuggestions();
         if (mToolbarTabController != null) mToolbarTabController.openHomepage();
     }
 }