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

ui/views/controls/glow_hover_controller.h

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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_CONTROLS_GLOW_HOVER_CONTROLLER_H_
 #define UI_VIEWS_CONTROLS_GLOW_HOVER_CONTROLLER_H_
 #pragma once
 
 #include "ui/base/animation/animation_delegate.h"
 #include "ui/base/animation/slide_animation.h"
 #include "ui/views/views_export.h"
 
 namespace gfx {
-class Canvas;
+class CanvasSkia;
 class Point;
 }
 
 class SkBitmap;
 
 namespace views {
 
 class View;
 
 // GlowHoverController is responsible for drawing a hover effect as is used by
@@ skipping 27 matching lines @@
 
   // Returns the value of the animation.
   double GetAnimationValue() const;
 
   // Returns true if there is something to be drawn. Use this instead of
   // invoking Draw() if creating |mask_image| is expensive.
   bool ShouldDraw() const;
 
   // If the hover is currently visible it is drawn to the supplied canvas.
   // |mask_image| is used to determine what parts of the canvas to draw on.
-  void Draw(gfx::Canvas* canvas, const SkBitmap& mask_image) const;
+  void Draw(gfx::CanvasSkia* canvas, const SkBitmap& mask_image) const;
 
   // ui::AnimationDelegate overrides:
   virtual void AnimationEnded(const ui::Animation* animation) OVERRIDE;
   virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
 
  private:
   // View we're drawing to.
   views::View* view_;
 
   // Opacity of the glow ramps up over time.
   ui::SlideAnimation animation_;
 
   // Location of the glow, relative to view.
   gfx::Point location_;
 
   DISALLOW_COPY_AND_ASSIGN(GlowHoverController);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_GLOW_HOVER_CONTROLLER_H_