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

ui/views/widget/native_widget_delegate.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_WIDGET_NATIVE_WIDGET_DELEGATE_H_
 #define UI_VIEWS_WIDGET_NATIVE_WIDGET_DELEGATE_H_
 #pragma once
 
 #include "ui/base/events.h"
 #include "ui/views/views_export.h"
 
 namespace gfx {
-class Canvas;
+class CanvasSkia;
 class Point;
 class Size;
 }
 
 namespace views {
 class InputMethod;
 class GestureEvent;
 class KeyEvent;
 class MouseEvent;
 class TouchEvent;
@@ skipping 58 matching lines @@
   // Returns true if the delegate has a FocusManager.
   virtual bool HasFocusManager() const = 0;
 
   // Paints the widget using acceleration. If the widget is not using
   // accelerated painting this returns false and does nothing.
   virtual bool OnNativeWidgetPaintAccelerated(
       const gfx::Rect& dirty_region) = 0;
 
   // Paints the rootview in the canvas. This will also refresh the compositor
   // tree if necessary when accelerated painting is enabled.
-  virtual void OnNativeWidgetPaint(gfx::Canvas* canvas) = 0;
+  virtual void OnNativeWidgetPaint(gfx::CanvasSkia* canvas) = 0;
 
   // Returns the non-client component (see ui/base/hit_test.h) containing
   // |point|, in client coordinates.
   virtual int GetNonClientComponent(const gfx::Point& point) = 0;
 
   // Mouse and key event handlers.
   virtual bool OnKeyEvent(const KeyEvent& event) = 0;
   virtual bool OnMouseEvent(const MouseEvent& event) = 0;
   virtual void OnMouseCaptureLost() = 0;
   virtual ui::TouchStatus OnTouchEvent(const TouchEvent& event) = 0;
   virtual ui::GestureStatus OnGestureEvent(const GestureEvent& event) = 0;
 
   // Runs the specified native command. Returns true if the command is handled.
   virtual bool ExecuteCommand(int command_id) = 0;
 
   // Returns the input method of the widget this delegate is associated with.
   // Note that this does not use the top level widget, so may return NULL
   // if the widget doesn't have input method.
   virtual InputMethod* GetInputMethodDirect() = 0;
 
   //
   virtual Widget* AsWidget() = 0;
   virtual const Widget* AsWidget() const = 0;
 };
 
 }  // namespace internal
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_NATIVE_WIDGET_DELEGATE_H_