Rename paint data structures

cc/input/scrollbar.h

 // Copyright 2013 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 CC_INPUT_SCROLLBAR_H_
 #define CC_INPUT_SCROLLBAR_H_
 
 #include "cc/base/cc_export.h"
+#include "cc/paint/paint_canvas.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/rect.h"
 
-class SkCanvas;
-
 namespace cc {
 
 enum ScrollbarOrientation { HORIZONTAL, VERTICAL };
 enum ScrollDirection { SCROLL_BACKWARD, SCROLL_FORWARD };
 // For now, TRACK includes everything but the thumb including background and
 // buttons.
 enum ScrollbarPart { THUMB, TRACK };
 
 class Scrollbar {
  public:
   virtual ~Scrollbar() {}
 
   virtual ScrollbarOrientation Orientation() const = 0;
   virtual bool IsLeftSideVerticalScrollbar() const = 0;
   virtual gfx::Point Location() const = 0;
   virtual bool IsOverlay() const = 0;
   virtual bool HasThumb() const = 0;
   virtual int ThumbThickness() const = 0;
   virtual int ThumbLength() const = 0;
   virtual gfx::Rect TrackRect() const = 0;
   virtual float ThumbOpacity() const = 0;
   virtual bool NeedsPaintPart(ScrollbarPart part) const = 0;
-  virtual void PaintPart(SkCanvas* canvas,
+  virtual void PaintPart(PaintCanvas* canvas,
                          ScrollbarPart part,
                          const gfx::Rect& content_rect) = 0;
 };
 
 }  // namespace cc
 
 #endif  // CC_INPUT_SCROLLBAR_H_