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

ui/views/painter.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_PAINTER_H_
 #define UI_VIEWS_PAINTER_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/views/views_export.h"
 
 class SkBitmap;
 
 namespace gfx {
-class Canvas;
+class CanvasSkia;
 class Insets;
 class Rect;
 class Size;
 }
 
 namespace views {
 
 // Painter, as the name implies, is responsible for painting in a particular
 // region. Think of Painter as a Border or Background that can be painted
 // in any region of a View.
 class VIEWS_EXPORT Painter {
  public:
   // A convenience method for painting a Painter in a particular region.
   // This translates the canvas to x/y and paints the painter.
-  static void PaintPainterAt(gfx::Canvas* canvas,
+  static void PaintPainterAt(gfx::CanvasSkia* canvas,
                              Painter* painter,
                              const gfx::Rect& rect);
 
   // Creates a painter that draws a gradient between the two colors.
   static Painter* CreateHorizontalGradient(SkColor c1, SkColor c2);
   static Painter* CreateVerticalGradient(SkColor c1, SkColor c2);
 
   // Creates a painter that divides |image| into nine regions. The four corners
   // are rendered at the size specified in insets (for example, the upper
   // left corners is rendered at 0x0 with a size of
   // insets.left()xinsets.right()). The four edges are stretched to fill the
   // destination size.
   // Ownership is passed to the caller.
   static Painter* CreateImagePainter(const SkBitmap& image,
                                      const gfx::Insets& insets,
                                      bool paint_center);
 
   virtual ~Painter() {}
 
   // Paints the painter in the specified region.
-  virtual void Paint(gfx::Canvas* canvas, const gfx::Size& size) = 0;
+  virtual void Paint(gfx::CanvasSkia* canvas, const gfx::Size& size) = 0;
 };
 
 // HorizontalPainter paints 3 images into a box: left, center and right. The
 // left and right images are drawn to size at the left/right edges of the
 // region. The center is tiled in the remaining space. All images must have the
 // same height.
 class VIEWS_EXPORT HorizontalPainter : public Painter {
  public:
   // Constructs a new HorizontalPainter loading the specified image names.
   // The images must be in the order left, right and center.
   explicit HorizontalPainter(const int image_resource_names[]);
 
   virtual ~HorizontalPainter() {}
 
   // Paints the images.
-  virtual void Paint(gfx::Canvas* canvas, const gfx::Size& size) OVERRIDE;
+  virtual void Paint(gfx::CanvasSkia* canvas, const gfx::Size& size) OVERRIDE;
 
   // Height of the images.
   int height() const { return height_; }
 
  private:
   // The image chunks.
   enum BorderElements {
     LEFT,
     CENTER,
     RIGHT
   };
 
   // The height.
   int height_;
   // NOTE: the images are owned by ResourceBundle. Don't free them.
   SkBitmap* images_[3];
 
   DISALLOW_COPY_AND_ASSIGN(HorizontalPainter);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_PAINTER_H_