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

chrome/renderer/resources/extensions/app_window_custom_bindings.js

Index: chrome/renderer/resources/extensions/app_window_custom_bindings.js
diff --git a/chrome/renderer/resources/extensions/app_window_custom_bindings.js b/chrome/renderer/resources/extensions/app_window_custom_bindings.js
index 04283fec5a0ed4059a0a36f007f8decec9d2bf11..f42829ac0b9915494de628350410379a7c8d5172 100644
--- a/chrome/renderer/resources/extensions/app_window_custom_bindings.js
+++ b/chrome/renderer/resources/extensions/app_window_custom_bindings.js
@@ -12,11 +12,10 @@ 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());