Fix the issue that wallpaper changes twice when both "onChanged" and "onAlarm" are fired.

chrome/browser/resources/chromeos/wallpaper_manager/js/util.js

 // Copyright (c) 2013 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.
 
 var WallpaperUtil = {
   strings: null,  // Object that contains all the flags
   syncFs: null,   // syncFileSystem handler
   webkitFs: null  // webkitFileSystem handler
 };
 
@@ skipping 305 matching lines @@
     xhr = new XMLHttpRequest();
 
   try {
     // Do not use loadend here to handle both success and failure case. It gets
     // complicated with abortion. Unexpected error message may show up. See
     // http://crbug.com/242581.
     xhr.addEventListener('load', function(e) {
       if (this.status == 200) {
         onSuccess(this);
       } else {
-        onFailure();
+        onFailure(this.status);
       }
     });
     xhr.addEventListener('error', onFailure);
     xhr.open('GET', url, true);
     xhr.responseType = type;
     xhr.send(null);
   } catch (e) {
     onFailure();
   }
 };
@@ skipping 30 matching lines @@
  * Runs chrome.test.sendMessage in test environment. Does nothing if running
  * in production environment.
  *
  * @param {string} message Test message to send.
  */
 WallpaperUtil.testSendMessage = function(message) {
   var test = chrome.test || window.top.chrome.test;
   if (test)
     test.sendMessage(message);
 };