[Sync] Speed up Javascript node operations

chrome/browser/resources/sync_internals/chrome_sync.js

 // Copyright (c) 2011 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 chrome = chrome || {};
 // TODO(akalin): Add mocking code for e.g. chrome.send() so that we
 // can test this without rebuilding chrome.
 chrome.sync = chrome.sync || {};
 (function () {
 
@@ skipping 122 matching lines @@
 var syncFunctions = [
   // Sync service functions.
   'getAboutInfo',
 
   // Notification functions.
   'getNotificationState',
   'getNotificationInfo',
 
   // Node lookup functions.
   'getRootNode',
-  'getNodeById',
+  'getNodesById',
+  'getChildNodeIds',
   'findNodesContainingString'
 ];
 
 for (var i = 0; i < syncFunctions.length; ++i) {
   var syncFunction = syncFunctions[i];
   chrome.sync[syncFunction] = makeSyncFunction(syncFunction);
 }
 
 })();