Fix MediaGalleriesPlatformAppBrowserTest tests with PlzNavigate.

chrome/test/data/extensions/api_test/media_galleries/picasa/test.js

 // Copyright 2013 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 mediaGalleries = chrome.mediaGalleries;
 var expectedGalleryEntryLength; // Size of ../common/test.jpg.
 
 //Verifies a directory itself, then the contents.
 function getAndVerifyDirectoryEntry(parentEntry, directoryName,
                                     verifyFunction) {
@@ skipping 141 matching lines @@
       }
     }
     chrome.test.fail("Picasa gallery not found");
   }
 
   return function() {
     getMediaFileSystemsList();
   }
 }
 
-CreateDummyWindowToPreventSleep();
-
 chrome.test.getConfig(function(config) {
   customArg = JSON.parse(config.customArg);
   expectedGalleryEntryLength = customArg[0];
 
   chrome.test.runTests([
     getTest(GalleryPropertiesTest),
     getTest(RootListingTest),
     getTest(AlbumsListingTest),
     getTest(FoldersListingTest),
     getTest(Album1ListingTest),
     getTest(Album2ListingTest),
     getTest(Folder1ListingTest),
     getTest(Folder2ListingTest),
   ]);
 });