Fix CrSettingsPrivacyPageTest.PrivacyPage test failure.

chrome/test/data/webui/settings/privacy_page_test.js

 // Copyright 2016 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.
 
 cr.define('settings_privacy_page', function() {
   /**
    * @constructor
    * @extends {TestBrowserProxy}
    * @implements {settings.PrivacyPageBrowserProxy}
    */
@@ skipping 165 matching lines @@
               var notice = element.$$('#notice');
               assertTrue(!!notice);
               var noticeActionButton = notice.$$('.action-button');
               assertTrue(!!noticeActionButton);
 
               assertTrue(element.$.dialog.open);
               assertTrue(notice.$.dialog.open);
 
               MockInteractions.tap(noticeActionButton);
 
-              // Tapping the action button will close the notice. Move to the
-              // end of the message loop to allow the closing event to propagate
-              // to the parent dialog. The parent dialog should subsequently
-              // close as well.
-              setTimeout(function() {
-                var notice = element.$$('#notice');
-                assertFalse(!!notice);
-                assertFalse(element.$.dialog.open);
-              }, 0);
+              return new Promise(function(resolve, reject) {
+                // Tapping the action button will close the notice. Move to the
+                // end of the message loop to allow the closing event to
+                // propagate to the parent dialog. The parent dialog should
+                // subsequently close as well.
+                setTimeout(function() {
+                  var notice = element.$$('#notice');
+                  assertFalse(!!notice);
+                  assertFalse(element.$.dialog.open);
+                  resolve();
+                }, 0);
+              });
             });
       });
 
       test('Counters', function() {
         assertTrue(element.$.dialog.open);
 
         // Initialize the browsing history pref, which should belong to the
         // first checkbox in the dialog.
         element.set('prefs', {
           browser: {
@@ skipping 26 matching lines @@
 
   return {
     registerTests: function() {
       if (cr.isMac || cr.isWin)
         registerNativeCertificateManagerTests();
 
       registerClearBrowsingDataTests();
     },
   };
 });