Enable tests related to the extensions web ui that were flaky.

chrome/browser/resources/extensions/extensions.js

 // Copyright (c) 2012 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.
 
 <include src="../../../../ui/webui/resources/js/cr/ui/focus_row.js">
 <include src="../../../../ui/webui/resources/js/cr/ui/focus_grid.js">
 <include src="../uber/uber_utils.js">
 <include src="extension_code.js">
 <include src="extension_commands_overlay.js">
 <include src="extension_error_overlay.js">
@@ skipping 327 matching lines @@
       var buttons = devControls.querySelector('.button-container');
       Array.prototype.forEach.call(buttons.querySelectorAll('a, button'),
                                    function(control) {
         control.tabIndex = showDevControls ? 0 : -1;
       });
       buttons.setAttribute('aria-hidden', !showDevControls);
 
       window.requestAnimationFrame(function() {
         devControls.style.height = !showDevControls ? '' :
             buttons.offsetHeight + 'px';
+
+        if (this.testingDeveloperModeCallback)

[not at google - send to devlin, 2015/04/29 22:03:31]

Where is this defined?

[hcarmona, 2015/04/30 18:42:00]

Defined now.

+          this.testingDeveloperModeCallback();
       }.bind(this));
     },
   };
 
   ExtensionSettings.onExtensionsChanged = function() {
     ExtensionSettings.getInstance().update_();
   };
 
   /**
    * Returns the current overlay or null if one does not exist.
@@ skipping 100 matching lines @@
   // Export
   return {
     ExtensionSettings: ExtensionSettings
   };
 });
 
 window.addEventListener('load', function(e) {
   document.documentElement.classList.add('loading');
   extensions.ExtensionSettings.getInstance().initialize();
 });