Simplify volume manager in Files app.

chrome/browser/resources/file_manager/foreground/js/file_tasks.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.
 
 'use strict';
 
 /**
  * This object encapsulates everything related to tasks execution.
  *
  * TODO(hirono): Pass each component instead of the entire FileManager.
@@ skipping 684 matching lines @@
   galleryFrame.onload = function() {
     galleryFrame.contentWindow.ImageUtil.metrics = metrics;
 
     // TODO(haruki): isOnReadonlyDirectory() only checks the permission for the
     // root. We should check more granular permission to know whether the file
     // is writable or not.
     var readonly = fm.isOnReadonlyDirectory();
     var currentDir = fm.getCurrentDirectoryEntry();
     var downloadsVolume =
         fm.volumeManager.getCurrentProfileVolumeInfo(RootType.DOWNLOADS);
-    var downloadsDir = downloadsVolume && downloadsVolume.root;
+    var downloadsDir = downloadsVolume && downloadsVolume.fileSystem.root;
     var readonlyDirName = null;
     if (readonly && currentDir) {
       // TODO(mtomasz): Pass Entry instead of localized name. Conversion to a
       //     display string should be done in gallery.js.
       var locationInfo = fm.volumeManager.getLocationInfo(currentDir);
       if (locationInfo && locationInfo.isRootEntry) {
         readonlyDirName = PathUtil.getRootTypeLabel(currentDir.rootType) ||
             currentDir.name;
       } else {
         readonlyDirName = currentDir.name;
@@ skipping 156 matching lines @@
       this.pendingInvocations_.push([privateMethod, arguments]);
     }
     return this;
   };
 };
 
 FileTasks.decorate('display');
 FileTasks.decorate('updateMenuItem');
 FileTasks.decorate('execute');
 FileTasks.decorate('executeDefault');