Fix flaky logo spin animation restart logic

chrome/browser/resources/help/help_page.js

 // Copyright 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.
 
 cr.define('help', function() {
   var Page = cr.ui.pageManager.Page;
   var PageManager = cr.ui.pageManager.PageManager;
 
   /**
    * Encapsulated handling of the About page. Called 'help' internally to avoid
@@ skipping 147 matching lines @@
 
         // Unhide the regulatory label if/when the image loads.
         $('regulatory-label').onload = function() {
           $('regulatory-label-container').hidden = false;
         };
       }
 
       var logo = $('product-logo');
       logo.onclick = function(e) {
         logo.classList.remove('spin');
-        setTimeout(function() { logo.classList.add('spin'); }, 0);
+        // Force a style recalc that cancels the animation specified by "spin".
+        getComputedStyle(logo).getPropertyValue('animation-name');
+        logo.classList.add('spin');
       };
 
       // Attempt to update.
       chrome.send('onPageLoaded');
     },
 
     /** @override */
     didClosePage: function() {
       this.setMoreInfoVisible_(false);
     },
@@ skipping 492 matching lines @@
   HelpPage.setRegulatoryLabelText = function(text) {
     assert(cr.isChromeOS);
     HelpPage.getInstance().setRegulatoryLabelText_(text);
   };
 
   // Export
   return {
     HelpPage: HelpPage
   };
 });