Implement AutomationNode.querySelector().

chrome/test/data/extensions/api_test/automation/tests/tabs/close_tab.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.
 
 var allTests = [
   function testCloseTab() {
-    getUrlFromConfig(function(url) {
+    getUrlFromConfig('index.html', function(url) {
       chrome.tabs.create({'url': url}, function(tab) {
         chrome.automation.getTree(function(rootNode) {
           rootNode.addEventListener(EventType.destroyed, function() {
             // Should get a 'destroyed' event when the tab is closed.
             // TODO(aboxhall): assert actual cleanup has occurred once
             // crbug.com/387954 makes it possible.
             chrome.test.succeed();
           });
           chrome.tabs.remove(tab.id);
         });
       });
     });
   }
 ]
 chrome.test.runTests(allTests);