Enable gallery watches on Mac

chrome/test/data/extensions/api_test/media_galleries_private/gallerywatch/test.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.
 
 var galleries;
 var invalidGalleryId = '11000';
 
 // chrome.mediaGalleries.getMediaFileSystems callback.
 var mediaFileSystemsListCallback = function (results) {
   galleries = results;
@@ skipping 15 matching lines @@
 
 // chrome.mediaGalleries.getAllGalleryWatch callback.
 var getAllGalleryWatchCallback = function (results) {
   if (!results) {
     chrome.test.sendMessage('get_all_gallery_watch_failed');
     return;
   }
   if (results.length == 0) {
     chrome.test.sendMessage('gallery_watchers_does_not_exists');
   } else {
-    var gallery_ids_str = "";
-    for (var i = 0; i < results.length; ++i) {
-      if (gallery_ids_str != "")
-        gallery_ids_str += ", ";
-      gallery_ids_str += results[i];
+    for (var i = 0; i < results.lendth; ++i) {
+      var info = chrome.mediaGalleries.getMediaFileSystemMetadata(galleries[i]);
+      if (results[i] !== info.galleryId) {
+        chrome.test.sendMessage('gallery_watcher_mismatch');
+        return;
+      }
     }
-    chrome.test.sendMessage(
-       'watchers_for_galleries_{' + gallery_ids_str + '}_found');
+    chrome.test.sendMessage('gallery_watcher_checks');
   }
 };
 
 // Helpers to add and remove event listeners.
 function addGalleryChangedListener() {
   chrome.mediaGalleriesPrivate.onGalleryChanged.addListener(
       onGalleryChangedCallback);
   chrome.test.sendMessage('add_gallery_changed_listener_ok');
 };
 
@@ skipping 33 matching lines @@
 
 function getAllWatchedGalleryIds() {
   chrome.mediaGalleriesPrivate.getAllGalleryWatch(getAllGalleryWatchCallback);
   chrome.test.sendMessage('get_all_gallery_watch_ok');
 };
 
 function removeAllGalleryWatch() {
   chrome.mediaGalleriesPrivate.removeAllGalleryWatch();
   chrome.test.sendMessage('remove_all_gallery_watch_ok');
 };