Allow requesting Automation tree by tabId

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) {
   delete state[StateType.horizontal];
   delete state[StateType.hovered];
   delete state[StateType.vertical];
 };
 
 var allTests = [
   function testSimplePage() {
     var title = tree.root.attributes.docTitle;
     assertEq('Automation Tests', title);
     RemoveUntestedStates(tree.root.state);
     assertEq(
       {enabled: true, focusable: true, readOnly: true},
       tree.root.state);
     var children = tree.root.children();
     assertEq(1, children.length);
-
     var body = children[0];
     assertEq('body', body.attributes.htmlTag);
 
     RemoveUntestedStates(body.state);
     assertEq({enabled: true, readOnly: true},
-             body.state);
+               body.state);
 
     var contentChildren = body.children();
     assertEq(3, contentChildren.length);
     var okButton = contentChildren[0];
     assertEq('Ok', okButton.attributes.name);
     RemoveUntestedStates(okButton.state);
     assertEq({enabled: true, focusable: true, readOnly: true},
              okButton.state);
     var userNameInput = contentChildren[1];
     assertEq('Username',
@@ skipping 31 matching lines @@
     assertEq(cancelButton, userNameInput.nextSibling());
 
     assertEq(userNameInput, cancelButton.previousSibling());
     assertEq(undefined, cancelButton.nextSibling());
 
     chrome.test.succeed();
   }
 ];
 
 setUpAndRunTests(allTests);