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

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

 // Copyright 2014 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;
 
 /**
  * Contains all of the command line switches that are specific to the chrome/
  * portion of Chromium on Android.
  */
@@ skipping 161 matching lines @@
      * Enable the menu trimming that removes "Bookmarks" and "Recent tabs" menu items.
      */
     public static final String ENABLE_MENU_TRIMMING = "enable-menu-trimming";
 
     /**
      * Disable speculative TCP/IP preconnection.
      * Native switch - switches::kDisablePreconnect
      */
     public static final String DISABLE_PRECONNECT = "disable-preconnect";
 
+    /**
+     * Specifies Android phone page loading progress bar animation.
+     * Native switch - switches::kProgressBarAnimation
+     */
+    public static final String PROGRESS_BAR_ANIMATION = "progress-bar-animation";
+
     // Prevent instantiation.
     private ChromeSwitches() {}
 }