Change ImageLoaderClient to return width and height of image.

ui/file_manager/image_loader/image_loader_client_unittest.js

 // 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.
 
 'use strict';
 
 var chrome = {
   metricsPrivate: {
     recordPercentage: function() {},
     recordValue: function() {}
@@ skipping 11 matching lines @@
  * @param {string} url URL
  * @param {Object} options load options.
  * @return {Promise<boolean>} True if the local cache is used.
  */
 function loadAndCheckCacheUsed(client, url, options) {
   var cacheUsed = true;
 
   ImageLoaderClient.sendMessage_ = function(message, callback) {
     cacheUsed = false;
     if (callback)
-      callback({data: 'ImageData', status: 'success'});
+      callback({data: 'ImageData', width: 100, height: 100, status: 'success'});
   };
 
   return new Promise(function(fulfill) {
     client.load(url, function() {
       fulfill(cacheUsed);
     }, options);
   });
 }
 
 function testCache(callback) {
@@ skipping 34 matching lines @@
       loadAndCheckCacheUsed(client, 'data:URI', {cache: true}).
       then(function(cacheUsed) {
         assertFalse(cacheUsed);
         return loadAndCheckCacheUsed(client, 'data:URI', {cache: true});
       }).
       then(function(cacheUsed) {
         assertFalse(cacheUsed);
       }),
       callback);
 }