Keep track of accessibility focus across windows.

chrome/test/data/extensions/api_test/automation/tests/tabs/sanity_check.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.
 
 // Do not test orientation or hover attributes (similar to exclusions on native
 // accessibility), since they can be inconsistent depending on the environment.
 var RemoveUntestedStates = function(state) {
   var result = JSON.parse(JSON.stringify(state));
   delete result[StateType.horizontal];
   delete result[StateType.hovered];
   delete result[StateType.vertical];
   return result;
 };
 
 var allTests = [
   function testSimplePage() {
     var title = rootNode.docTitle;
     assertEq('Automation Tests', title);
 
     var state = RemoveUntestedStates(rootNode.state);
     assertEq(
-        {enabled: true, focusable: true, readOnly: true},
+        {enabled: true, focusable: true, readOnly: true, focused: true},
         state);
 
     var children = rootNode.children;
     assertEq(RoleType.rootWebArea, rootNode.role);
     assertEq(1, children.length);
     var body = children[0];
     assertEq('body', body.htmlTag);
     state = RemoveUntestedStates(body.state);
     assertEq({enabled: true, readOnly: true}, state);
 
@@ skipping 41 matching lines @@
     chrome.test.succeed();
   },
   function testIsRoot() {
     assertTrue(rootNode.isRootNode);
     assertFalse(rootNode.firstChild.isRootNode);
     chrome.test.succeed();
   }
 ];
 
 setUpAndRunTests(allTests);