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

ui/views/controls/menu/submenu_view.h

Index: ui/views/controls/menu/submenu_view.h
diff --git a/ui/views/controls/menu/submenu_view.h b/ui/views/controls/menu/submenu_view.h
index 40981a25605162886cab14c6adbeaff36bdb1c86..9b757023939b4f25a5a4c4fdeaebe5363fb2d906 100644
--- a/ui/views/controls/menu/submenu_view.h
+++ b/ui/views/controls/menu/submenu_view.h
@@ -60,7 +60,7 @@ class VIEWS_EXPORT SubmenuView : public View,
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
 
   // Painting.
-  virtual void PaintChildren(gfx::Canvas* canvas) OVERRIDE;
+  virtual void PaintChildren(gfx::CanvasSkia* canvas) OVERRIDE;
 
   // Drag and drop methods. These are forwarded to the MenuController.
   virtual bool GetDropFormats(
@@ -164,7 +164,7 @@ class VIEWS_EXPORT SubmenuView : public View,
  private:
   // Paints the drop indicator. This is only invoked if item is non-NULL and
   // position is not DROP_NONE.
-  void PaintDropIndicator(gfx::Canvas* canvas,
+  void PaintDropIndicator(gfx::CanvasSkia* canvas,
                           MenuItemView* item,
                           MenuDelegate::DropPosition position);