Re-enable native UI for {frame:'chrome'} in app windows.

chrome/renderer/resources/extensions/app_window_custom_bindings.js

 // Copyright (c) 2012 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.
 
 // Custom bindings for the app_window API.
 
 var chromeHidden = requireNative('chrome_hidden').GetChromeHidden();
 var sendRequest = require('sendRequest').sendRequest;
 var appWindowNatives = requireNative('app_window');
 var forEach = require('utils').forEach;
 var GetView = appWindowNatives.GetView;
 
 chromeHidden.registerCustomHook('app.window', function(bindingsAPI) {
   var apiFunctions = bindingsAPI.apiFunctions;
-  apiFunctions.setCustomCallback('create', function(name, request, viewId) {
+  apiFunctions.setCustomCallback('create', function(name, request, result) {
     var view = null;
-    if (viewId) {
-      var shouldShowFrame = !request.args[1] || request.args[1].frame != 'none';
-      view = GetView(viewId, !!shouldShowFrame);
+    if (result.viewId) {
+      view = GetView(result.viewId, result.injectTitlebar);
     }
     if (request.callback) {
       request.callback(view.chrome.app.window.current());
       delete request.callback;
     }
   })
   var AppWindow = function() {};
   forEach(chromeHidden.internalAPIs.app.currentWindowInternal, function(fn) {
     AppWindow.prototype[fn] =
         chromeHidden.internalAPIs.app.currentWindowInternal[fn];
   });
   AppWindow.prototype.moveTo = window.moveTo.bind(window);
   AppWindow.prototype.resizeTo = window.resizeTo.bind(window);
   AppWindow.prototype.contentWindow = window;
   // So as not to break apps that use .dom. http://crbug.com/147668
   // TODO(jeremya): remove this once M23 has branched.
   AppWindow.prototype.dom = window;
   apiFunctions.setHandleRequest('current', function() {
     return new AppWindow;
   })
 });