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

ash/launcher/tabbed_launcher_button.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 ASH_LAUNCHER_TABBED_LAUNCHER_BUTTON_H_
 #define ASH_LAUNCHER_TABBED_LAUNCHER_BUTTON_H_
 #pragma once
 
 #include "base/memory/scoped_ptr.h"
 #include "base/timer.h"
@@ skipping 18 matching lines @@
   virtual ~TabbedLauncherButton();
 
   // Notification that the images are about to change. Kicks off an animation.
   void PrepareForImageChange();
 
   // Sets the images to display for this entry.
   void SetTabImage(const SkBitmap& image, int count);
 
  protected:
   // View overrides:
-  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
+  virtual void OnPaint(gfx::CanvasSkia* canvas) OVERRIDE;
   virtual bool OnMousePressed(const views::MouseEvent& event) OVERRIDE;
   virtual void OnMouseReleased(const views::MouseEvent& event) OVERRIDE;
   virtual void OnMouseCaptureLost() OVERRIDE;
   virtual bool OnMouseDragged(const views::MouseEvent& event) OVERRIDE;
   virtual void OnMouseEntered(const views::MouseEvent& event) OVERRIDE;
   virtual void OnMouseMoved(const views::MouseEvent& event) OVERRIDE;
   virtual void OnMouseExited(const views::MouseEvent& event) OVERRIDE;
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
 
  private:
@@ skipping 47 matching lines @@
 
   views::GlowHoverController hover_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(TabbedLauncherButton);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_LAUNCHER_TABBED_LAUNCHER_BUTTON_H_