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

ui/views/painter.h

Index: ui/views/painter.h
diff --git a/ui/views/painter.h b/ui/views/painter.h
index dcdebb214328a436bb72afb14cf47a61a595ee74..3f53ae4fb1a8968dd552384d086920dd2c331389 100644
--- a/ui/views/painter.h
+++ b/ui/views/painter.h
@@ -14,7 +14,7 @@
 class SkBitmap;
 
 namespace gfx {
-class Canvas;
+class CanvasSkia;
 class Insets;
 class Rect;
 class Size;
@@ -29,7 +29,7 @@ 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);
 
@@ -50,7 +50,7 @@ class VIEWS_EXPORT Painter {
   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
@@ -66,7 +66,7 @@ class VIEWS_EXPORT HorizontalPainter : public Painter {
   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_; }