Fix stocks app test

sky/examples/stocks2/lib/stock_app.dart

 // Copyright 2015 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.
 
+import 'package:sky/rendering/box.dart';
 import 'package:sky/widgets/basic.dart';
 import 'package:sky/widgets/navigator.dart';
 import 'package:sky/widgets/widget.dart';
 
 import 'stock_home.dart';
 import 'stock_settings.dart';
 
 class StocksApp extends App {
+
+  StocksApp({ RenderView renderViewOverride }) : super(renderViewOverride: renderViewOverride);
+
   Widget build() {
     return new Navigator(
       routes: [
         new Route(
           name: '/', 
           builder: (navigator) => new StockHome(navigator)
         ),
         new Route(
           name: '/settings', 
           builder: (navigator) => new StockSettings(navigator)
         ),
       ]
     );
   }
 }
 
 void main() {
   print("starting stocks app!");
   App app = new StocksApp();
   WidgetAppView.appView.onFrame = () {
     // uncomment this for debugging:
     // WidgetAppView.appView.debugDumpRenderTree();
   };
 }