[File Manager] Properly enable/disable Copy and Open for GData files in the offline mode.

chrome/browser/resources/file_manager/js/directory_model.js

 // Copyright (c) 2012 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.
 
 // If directory files changes too often, don't rescan directory more than once
 // per specified interval
 var SIMULTANEOUS_RESCAN_INTERVAL = 1000;
 // Used for operations that require almost instant rescan.
 var SHORT_RESCAN_INTERVAL = 100;
 
@@ skipping 135 matching lines @@
  */
 DirectoryModel.prototype.isPathReadOnly = function(path) {
   switch (DirectoryModel.getRootType(path)) {
     case DirectoryModel.RootType.REMOVABLE:
       return !!this.volumeReadOnlyStatus_[DirectoryModel.getRootPath(path)];
     case DirectoryModel.RootType.ARCHIVE:
       return true;
     case DirectoryModel.RootType.DOWNLOADS:
       return false;
     case DirectoryModel.RootType.GDATA:
-      return !navigator.onLine;
+      return util.isOffline();
     default:
       return true;
   }
 };
 
 /**
  * @return {boolean} If current directory is system.
  */
 DirectoryModel.prototype.isSystemDirectory = function() {
   var path = this.currentDirEntry_.fullPath;
@@ skipping 1070 matching lines @@
 /**
  * @private
  */
 DirectoryModel.Scanner.prototype.recordMetrics_ = function() {
   metrics.recordInterval('DirectoryScan');
   if (this.dir_.fullPath ==
       '/' + DirectoryModel.DOWNLOADS_DIRECTORY) {
     metrics.recordMediumCount('DownloadsCount', this.list_.length);
   }
 };