Explicitly specify contents scale for SurfaceLayer.

cc/layers/surface_layer.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 CC_LAYERS_SURFACE_LAYER_H_
 #define CC_LAYERS_SURFACE_LAYER_H_
 
 #include "cc/base/cc_export.h"
 #include "cc/layers/layer.h"
 #include "cc/surfaces/surface_id.h"
@@ skipping 12 matching lines @@
   using SatisfyCallback = base::Callback<void(SurfaceSequence)>;
 
   // This callback is run to require that a specific SurfaceSequence is
   // received before a SurfaceId is destroyed.
   using RequireCallback = base::Callback<void(SurfaceId, SurfaceSequence)>;
 
   static scoped_refptr<SurfaceLayer> Create(
       const SatisfyCallback& satisfy_callback,
       const RequireCallback& require_callback);
 
-  void SetSurfaceId(SurfaceId surface_id, const gfx::Size& size);
+  void SetSurfaceId(SurfaceId surface_id, float scale, const gfx::Size& size);
 
   // Layer overrides.
   scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl) override;
   void SetLayerTreeHost(LayerTreeHost* host) override;
   void PushPropertiesTo(LayerImpl* layer) override;
   void CalculateContentsScale(float ideal_contents_scale,
                               float* contents_scale_x,
                               float* contents_scale_y,
                               gfx::Size* content_bounds) override;
 
  protected:
   SurfaceLayer(const SatisfyCallback& satisfy_callback,
                const RequireCallback& require_callback);
   bool HasDrawableContent() const override;
 
  private:
   ~SurfaceLayer() override;
   void CreateNewDestroySequence();
   void SatisfyDestroySequence();
 
   SurfaceId surface_id_;
   gfx::Size surface_size_;
+  float surface_scale_;
   SurfaceSequence destroy_sequence_;
   SatisfyCallback satisfy_callback_;
   RequireCallback require_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(SurfaceLayer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_SURFACE_LAYER_H_