Add the browser test for the new gallery.

chrome/test/data/extensions/api_test/file_manager_browsertest/file_display.js

-// Copyright (c) 2014 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';
-
-/**
- * Tests if the files initially added by the C++ side are displayed, and
- * that a subsequently added file shows up.
- *
- * @param {string} path Directory path to be tested.
- */
-function fileDisplay(path) {
-  var appId;
-
-  var expectedFilesBefore =
-      TestEntryInfo.getExpectedRows(path == RootPath.DRIVE ?
-          BASIC_DRIVE_ENTRY_SET : BASIC_LOCAL_ENTRY_SET).sort();
-
-  var expectedFilesAfter =
-      expectedFilesBefore.concat([ENTRIES.newlyAdded.getExpectedRow()]).sort();
-
-  StepsRunner.run([
-    function() {
-      setupAndWaitUntilReady(null, path, this.next);
-    },
-    // Notify that the list has been verified and a new file can be added
-    // in file_manager_browsertest.cc.
-    function(inAppId, actualFilesBefore) {
-      appId = inAppId;
-      chrome.test.assertEq(expectedFilesBefore, actualFilesBefore);
-      addEntries(['local', 'drive'], [ENTRIES.newlyAdded], this.next);
-    },
-    function(result) {
-      chrome.test.assertTrue(result);
-      waitForFileListChange(appId, expectedFilesBefore.length).then(this.next);
-    },
-    // Confirm the file list.
-    function(actualFilesAfter) {
-      chrome.test.assertEq(expectedFilesAfter, actualFilesAfter);
-      checkIfNoErrorsOccured(this.next);
-    },
-  ]);
-}
-
-testcase.fileDisplayDownloads = function() {
-  fileDisplay(RootPath.DOWNLOADS);
-};
-
-testcase.fileDisplayDrive = function() {
-  fileDisplay(RootPath.DRIVE);
-};