Implement automatic load of composed/embedded automation trees

chrome/test/data/extensions/api_test/automation/tests/unit/test.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.
 
 chrome.test.runWithModuleSystem(function(moduleSystem) {
   window.AutomationRootNode =
       moduleSystem.require('automationNode').AutomationRootNode;
   window.privates = moduleSystem.privates;
+  // Unused.
+  window.automationUtil = function() {};
+  window.automationUtil.storeTreeCallback = function() {};
 });
 
 var assertEq = chrome.test.assertEq;
 var assertFalse = chrome.test.assertFalse;
 var assertTrue = chrome.test.assertTrue;
 var assertIsDef = function(obj) {
   assertTrue(obj !== null && obj !== undefined);
 }
 var assertIsNotDef = function(obj) {
   assertTrue(obj === null || obj === undefined);
@@ skipping 194 matching lines @@
 
     // Make sure the name changes.
     assertTrue(privates(tree).impl.unserialize(update));
     assertEq('bar', button.attributes.name);
 
     succeed();
   }
 ];
 
 chrome.test.runTests(tests);