Plumb file system name down from MediaFileSystemRegistry.

chrome/renderer/resources/extensions/media_galleries_custom_bindings.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.
 
 // Custom bindings for the Media Gallery API.
 
 var mediaGalleriesNatives = requireNative('mediaGalleries');
 
 var chromeHidden = requireNative('chrome_hidden').GetChromeHidden();
 
 chromeHidden.registerCustomHook('mediaGalleries',
                                 function(bindingsAPI, extensionId) {
   var apiFunctions = bindingsAPI.apiFunctions;
 
   // getMediaFileSystems uses a custom callback so that it can instantiate and
   // return an array of file system objects.
   apiFunctions.setCustomCallback('getMediaFileSystems',
                                  function(name, request, response) {
     var result = null;
     if (response) {
       result = [];
       for (var i = 0; i < response.length; i++) {
         result.push(mediaGalleriesNatives.GetMediaFileSystemObject(
-            response[i].fsid, response[i].dirname));
+            response[i].fsid, response[i].name));
       }
     }
     if (request.callback)
       request.callback(result);
     request.callback = null;
   });
 });