ui/gfx: Make gfx::Canvas inherit from gfx::CanvasSkia.

ui/views/bubble/bubble_border.h

 // Copyright (c) 2012 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 UI_VIEWS_BUBBLE_BUBBLE_BORDER_H_
 #define UI_VIEWS_BUBBLE_BUBBLE_BORDER_H_
 #pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/views/background.h"
@@ skipping 110 matching lines @@
  private:
   struct BorderImages;
 
   // Loads images if necessary.
   static BorderImages* GetBorderImages(Shadow shadow);
 
   virtual ~BubbleBorder();
 
   // Overridden from views::Border:
   virtual void Paint(const views::View& view,
-                     gfx::Canvas* canvas) const OVERRIDE;
+                     gfx::CanvasSkia* canvas) const OVERRIDE;
 
-  void DrawEdgeWithArrow(gfx::Canvas* canvas,
+  void DrawEdgeWithArrow(gfx::CanvasSkia* canvas,
                          bool is_horizontal,
                          SkBitmap* edge,
                          SkBitmap* arrow,
                          int start_x,
                          int start_y,
                          int before_arrow,
                          int after_arrow,
                          int offset) const;
 
-  void DrawArrowInterior(gfx::Canvas* canvas,
+  void DrawArrowInterior(gfx::CanvasSkia* canvas,
                          bool is_horizontal,
                          int tip_x,
                          int tip_y,
                          int shift_x,
                          int shift_y) const;
 
   // Border graphics.
   struct BorderImages* images_;
 
   // Image bundles.
@@ skipping 17 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(BubbleBorder);
 };
 
 // A Background that clips itself to the specified BubbleBorder and uses
 // the background color of the BubbleBorder.
 class VIEWS_EXPORT BubbleBackground : public views::Background {
  public:
   explicit BubbleBackground(BubbleBorder* border) : border_(border) {}
 
   // Background overrides.
-  virtual void Paint(gfx::Canvas* canvas, views::View* view) const OVERRIDE;
+  virtual void Paint(gfx::CanvasSkia* canvas, views::View* view) const OVERRIDE;
 
  private:
   BubbleBorder* border_;
 
   DISALLOW_COPY_AND_ASSIGN(BubbleBackground);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_BUBBLE_BUBBLE_BORDER_H_