Fixing exit on 'X' icon in Photo Editor

chrome/browser/resources/file_manager/js/mock_chrome.js

 // Copyright (c) 2011 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.
 
 /**
  * Mock out the chrome.fileBrowserPrivate API for use in the harness.
  */
 chrome.fileBrowserPrivate = {
 
   /**
@@ skipping 41 matching lines @@
 
   /**
    * Disk mount/unmount notification.
    */
   onMountCompleted: {
     callbacks: [],
     addListener: function(cb) { this.callbacks.push(cb) }
   },
 
   /**
+   * File system change notification.
+   */
+  onFileChanged: {
+    callbacks: [],
+    addListener: function(cb) { this.callbacks.push(cb) }
+  },
+
+  /**
+   * File watchers.
+   */
+  addFileWatch: function(path, callback) { callback(true) },
+
+  removeFileWatch: function(path, callback) { callback(true) },
+
+  /**
    * Returns common tasks for a given list of files.
    */
   getFileTasks: function(urlList, callback) {
     if (urlList.length == 0)
       return callback([]);
 
     // This is how File Manager gets the extension id.
     var extensionId = chrome.extension.getURL('').split('/')[2];
 
     if (!callback)
@@ skipping 309 matching lines @@
 };
 
 chrome.experimental = {
   metrics: {
     recordValue: function() {},
     recordMediumCount: function() {},
     recordTime: function() {},
     recordUserAction: function() {}
   }
 };