Stocks app shouldn't show black when resuming from recents list

sky/shell/ui/engine.h

 // 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.
 
 #ifndef SKY_SHELL_UI_ENGINE_H_
 #define SKY_SHELL_UI_ENGINE_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 37 matching lines @@
 
   void Init();
 
   void BeginFrame(base::TimeTicks frame_time);
   skia::RefPtr<SkPicture> Paint();
 
  private:
   // UIDelegate methods:
   void ConnectToViewportObserver(
       mojo::InterfaceRequest<ViewportObserver> request) override;
+  void OnAcceleratedWidgetAvailable(gfx::AcceleratedWidget widget) override;
+  void OnOutputSurfaceDestroyed() override;
 
   // ViewportObserver:
   void OnViewportMetricsChanged(int width, int height,
                                 float device_pixel_ratio) override;
   void OnInputEvent(InputEventPtr event) override;
   void LoadURL(const mojo::String& url) override;
 
   // WebViewClient methods:
   void frameDetached(blink::WebFrame*) override;
   void initializeLayerTreeView() override;
   void scheduleVisualUpdate() override;
   blink::WebScreenInfo screenInfo() override;
   blink::ServiceProvider* services() override;
   void didCreateIsolate(blink::WebLocalFrame* frame,
                         Dart_Isolate isolate) override;
 
   // Services methods:
   mojo::NavigatorHost* NavigatorHost() override;
 
   // NavigatorHost methods:
   void RequestNavigate(mojo::Target target,
                        mojo::URLRequestPtr request) override;
   void DidNavigateLocally(const mojo::String& url) override;
   void RequestNavigateHistory(int32_t delta) override;
 
   mojo::ServiceProviderPtr CreateServiceProvider();
   void UpdateWebViewSize();
 
-  scoped_refptr<base::SingleThreadTaskRunner> java_task_runner_;
+  Config config_;
   mojo::ServiceProviderPtr service_provider_;
   scoped_ptr<PlatformImpl> platform_impl_;
   scoped_ptr<Animator> animator_;
   blink::WebView* web_view_;
   float device_pixel_ratio_;
   gfx::Size physical_size_;
   mojo::Binding<ViewportObserver> viewport_observer_binding_;
 
   base::WeakPtrFactory<Engine> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Engine);
 };
 
 }  // namespace shell
 }  // namespace sky
 
 #endif  // SKY_SHELL_UI_ENGINE_H_