Pass a ui::PaintContext from ui::Layer to layer delegates.

content/browser/web_contents/aura/shadow_layer_delegate.h

 // Copyright (c) 2013 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 CONTENT_BROWSER_WEB_CONTENTS_AURA_SHADOW_LAYER_DELEGATE_H_
 #define CONTENT_BROWSER_WEB_CONTENTS_AURA_SHADOW_LAYER_DELEGATE_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/compositor/layer_delegate.h"
@@ skipping 14 matching lines @@
  public:
   explicit ShadowLayerDelegate(ui::Layer* shadow_for);
   ~ShadowLayerDelegate() override;
 
   // Returns the layer for the shadow. Note that the ShadowLayerDelegate owns
   // the layer, and the layer is destroyed when the delegate is destroyed.
   ui::Layer* layer() { return layer_.get(); }
 
  private:
   // Overridden from ui::LayerDelegate:
-  void OnPaintLayer(gfx::Canvas* canvas) override;
+  void OnPaintLayer(const ui::PaintContext& context) override;
   void OnDelegatedFrameDamage(const gfx::Rect& damage_rect_in_dip) override;
   void OnDeviceScaleFactorChanged(float device_scale_factor) override;
   base::Closure PrepareForLayerBoundsChange() override;
 
   scoped_ptr<ui::Layer> layer_;
 
   DISALLOW_COPY_AND_ASSIGN(ShadowLayerDelegate);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_WEB_CONTENTS_AURA_SHADOW_LAYER_DELEGATE_H_