MD Settings: Deflake attempt for CrSettingsPrivacyPageTest.PrivacyPage.

chrome/test/data/webui/settings/about_page_tests.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_about_page', function() {
   /**
    * @constructor
    * @implements {settings.AboutPageBrowserProxy}
    * @extends {settings.TestBrowserProxy}
    */
@@ skipping 588 matching lines @@
           checkChangeChannelButton(true);
         });
 
         test('ChangeChannel_Disabled', function() {
           checkChangeChannelButton(false);
         });
       });
     }
 
     function registerChannelSwitcherDialogTests() {
-      /**
-       * Converts an event occurrence to a promise.
-       * @param {string} eventType
-       * @param {!HTMLElement} target
-       * @return {!Promise} A promise firing once the event occurs.
-       * TODO(dpapad); Share this code with certificate_manager_page_test.js
-       * identical helper method.
-       */
-      function eventToPromise(eventType, target) {
-        return new Promise(function(resolve, reject) {
-          target.addEventListener(eventType, resolve);
-        });
-      }
-
       suite('ChannelSwitcherDialogTest', function() {
         var dialog = null;
         var radioButtons = null;
         var browserProxy = null;
         var currentChannel = BrowserChannel.BETA;
 
         setup(function() {
           browserProxy = new TestAboutPageBrowserProxy();
           browserProxy.setChannels(currentChannel, currentChannel);
           settings.AboutPageBrowserProxyImpl.instance_ = browserProxy;
@@ skipping 31 matching lines @@
         test('ChangeChannel_LessStable', function() {
           assertEquals(BrowserChannel.DEV, radioButtons.item(2).name);
           MockInteractions.tap(radioButtons.item(2));
           Polymer.dom.flush();
 
           assertFalse(dialog.$.warning.hidden);
           // Check that only the "Change channel" button becomes visible.
           assertTrue(dialog.$.changeChannelAndPowerwash.hidden);
           assertFalse(dialog.$.changeChannel.hidden);
 
-          var whenTargetChannelChangedFired = eventToPromise(
+          var whenTargetChannelChangedFired = test_util.eventToPromise(
               'target-channel-changed', dialog);
 
           MockInteractions.tap(dialog.$.changeChannel);
           return browserProxy.whenCalled('setChannel').then(function(args) {
             assertEquals(BrowserChannel.DEV, args[0]);
             assertFalse(args[1]);
             return whenTargetChannelChangedFired;
           }).then(function(event) {
             assertEquals(BrowserChannel.DEV, event.detail);
           });
         });
 
         // Test case where user switches to a more stable channel.
         test('ChangeChannel_MoreStable', function() {
           assertEquals(BrowserChannel.STABLE, radioButtons.item(0).name);
           MockInteractions.tap(radioButtons.item(0));
           Polymer.dom.flush();
 
           assertFalse(dialog.$.warning.hidden);
           // Check that only the "Change channel and Powerwash" button becomes
           // visible.
           assertFalse(dialog.$.changeChannelAndPowerwash.hidden);
           assertTrue(dialog.$.changeChannel.hidden);
 
-          var whenTargetChannelChangedFired = eventToPromise(
+          var whenTargetChannelChangedFired = test_util.eventToPromise(
               'target-channel-changed', dialog);
 
           MockInteractions.tap(dialog.$.changeChannelAndPowerwash);
           return browserProxy.whenCalled('setChannel').then(function(args) {
             assertEquals(BrowserChannel.STABLE, args[0]);
             assertTrue(args[1]);
             return whenTargetChannelChangedFired;
           }).then(function(event) {
             assertEquals(BrowserChannel.STABLE, event.detail);
           });
         });
       });
     }
   }
 
   return {
     registerTests: function() {
       if (cr.isChromeOS) {
         registerDetailedBuildInfoTests();
         registerChannelSwitcherDialogTests();
       }
       registerAboutPageTests();
     },
     registerOfficialBuildTests: registerOfficialBuildTests,
   };
 });