[Files.app] Use 'activate' event on the view-change menuitems instead of 'click' event

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

 // Copyright (c) 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.
 
 'use strict';
 
 /**
  * @enum {string}
  * @const
  */
@@ skipping 1486 matching lines @@
       setupAndWaitUntilReady(appState, this.next);
     },
     // Check the initial view.
     function(inAppId) {
       appId = inAppId;
       callRemoteTestUtil('waitForElement',
                          appId,
                          ['.thumbnail-grid[hidden]'],
                          this.next);
     },
+    // Opens the gear menu.
+    function() {
+      callRemoteTestUtil('fakeMouseClick',
+                         appId,
+                         ['#gear-button'],
+                         this.next);
+    },
     // Change the current view.
     function() {
       callRemoteTestUtil('fakeMouseClick',
                          appId,
                          ['#thumbnail-view'],
                          this.next);
     },
     // Check the new current view.
     function(result) {
       chrome.test.assertTrue(result);
@@ skipping 272 matching lines @@
                          this.next);
     },
     // Verify the thumbnail.
     function(element) {
       chrome.test.assertTrue(element.attributes.src.indexOf(
           'data:image/jpeg') === 0);
       checkIfNoErrorsOccured(this.next);
     }
   ]);
 };