Make reftests work for sky.

sky/compositor/layer_host.h

 // Copyright 2014 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_COMPOSITOR_LAYER_HOST_H_
 #define SKY_COMPOSITOR_LAYER_HOST_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 23 matching lines @@
     return const_cast<mojo::GaneshContext*>(&ganesh_context_);
   }
 
   ResourceManager* resource_manager() const {
     return const_cast<ResourceManager*>(&resource_manager_);
   }
 
   void SetNeedsAnimate();
   void SetRootLayer(scoped_refptr<Layer> layer);
 
+  void GetPixelsForTesting(std::vector<unsigned char>* pixels);
+
  private:
   enum State {
     kWaitingForSurfaceService,
     kReadyForFrame,
     kWaitingForFrameAcknowldgement,
   };
 
   // SurfaceHolder::Client
   void OnSurfaceConnectionCreated() override;
   void OnSurfaceIdAvailable(mojo::SurfaceIdPtr surface_id) override;
@@ skipping 16 matching lines @@
   scoped_refptr<Layer> root_layer_;
 
   base::WeakPtrFactory<LayerHost> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerHost);
 };
 
 }  // namespace sky
 
 #endif  // SKY_COMPOSITOR_LAYER_HOST_H_