Add the browser test for the new gallery.

chrome/test/data/extensions/api_test/file_manager_browsertest/traverse.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';
-
-/**
- * Test utility for traverse tests.
- * @param {string} path Root path to be traversed.
- */
-function traverseDirectories(path) {
-  var appId;
-  StepsRunner.run([
-    // Set up File Manager. Do not add initial files.
-    function() {
-      openNewWindow(null, path, this.next);
-    },
-    // Check the initial view.
-    function(inAppId) {
-      appId = inAppId;
-      waitForElement(appId, '#detail-table').then(this.next);
-    },
-    function() {
-      addEntries(['local', 'drive'], NESTED_ENTRY_SET, this.next);
-    },
-    function(result) {
-      chrome.test.assertTrue(result);
-      waitForFiles(appId, [ENTRIES.directoryA.getExpectedRow()]).
-          then(this.next);
-    },
-    // Open the directory
-    function() {
-      callRemoteTestUtil('openFile', appId, ['A'], this.next);
-    },
-    // Check the contents of current directory.
-    function(result) {
-      chrome.test.assertTrue(result);
-      waitForFiles(appId, [ENTRIES.directoryB.getExpectedRow()]).
-          then(this.next);
-    },
-    // Open the directory
-    function() {
-      callRemoteTestUtil('openFile', appId, ['B'], this.next);
-    },
-    // Check the contents of current directory.
-    function(result) {
-      chrome.test.assertTrue(result);
-      waitForFiles(appId, [ENTRIES.directoryC.getExpectedRow()]).
-          then(this.next);
-    },
-    // Check the error.
-    function() {
-      checkIfNoErrorsOccured(this.next);
-    }
-  ]);
-}
-
-/**
- * Tests to traverse local directories.
- */
-testcase.traverseDownloads = function() {
-  traverseDirectories(RootPath.DOWNLOADS);
-};
-
-/**
- * Tests to traverse drive directories.
- */
-testcase.traverseDrive = function() {
-  traverseDirectories(RootPath.DRIVE);
-};