Match html canvas which is transferred to OffscreenCanvas to CSS style

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 "base/macros.h"
 #include "cc/base/cc_export.h"
 #include "cc/layers/layer.h"
@@ skipping 16 matching lines @@
   // received before a SurfaceId is destroyed.
   using RequireCallback =
       base::Callback<void(const SurfaceId&, const SurfaceSequence&)>;
 
   static scoped_refptr<SurfaceLayer> Create(
       const SatisfyCallback& satisfy_callback,
       const RequireCallback& require_callback);
 
   void SetSurfaceId(const SurfaceId& surface_id,
                     float scale,
-                    const gfx::Size& size);
+                    const gfx::Size& size,
+                    bool scale_layer_bounds_with_surface_size = false);

[danakj, 2016/11/28 22:26:22]

i'd prefer no default behaviour here, just update callsites.

[danakj, 2016/11/28 22:26:22]

also, I think "stretch_content_to_fill_bounds" might be a more clear name to
express intent. a comment that the |scale| is ununsed when this is true would be
helpful too.

[xlai (Olivia), 2016/12/13 17:29:18]

Done.

[xlai (Olivia), 2016/12/13 17:29:18]

Done.

 
   // Layer overrides.
   std::unique_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl) override;
   void SetLayerTreeHost(LayerTreeHost* host) override;
   void PushPropertiesTo(LayerImpl* layer) override;
 
   SurfaceId surface_id() const { return surface_id_; }
   const gfx::Size& surface_size() const { return surface_size_; }
   float surface_scale() const { return surface_scale_; }
 
   const SatisfyCallback& satisfy_callback() const { return satisfy_callback_; }
   const RequireCallback& require_callback() const { return require_callback_; }
 
  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_;
+  bool scale_layer_bounds_with_surface_size_;

[danakj, 2016/11/28 22:26:22]

 = false

[xlai (Olivia), 2016/12/13 17:29:18]

Done

   SurfaceSequence destroy_sequence_;
   SatisfyCallback satisfy_callback_;
   RequireCallback require_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(SurfaceLayer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_SURFACE_LAYER_H_