cc: Create a cc::ScrollbarThemePainter and an adapter class in compositor bindings.

cc/scrollbar_theme_painter.h

+// Copyright 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 CC_SCROLLBAR_THEME_PAINTER_H_
+#define CC_SCROLLBAR_THEME_PAINTER_H_
+
+#include "cc/cc_export.h"
+
+class SkCanvas;
+
+namespace gfx {
+class Rect;
+}
+
+namespace cc {
+
+class CC_EXPORT ScrollbarThemePainter {
+ public:
+  virtual ~ScrollbarThemePainter() {}
+
+  virtual void PaintScrollbarBackground(SkCanvas*, const gfx::Rect&) = 0;
+  virtual void PaintTrackBackground(SkCanvas*, const gfx::Rect&) = 0;
+  virtual void PaintBackTrackPart(SkCanvas*, const gfx::Rect&) = 0;
+  virtual void PaintForwardTrackPart(SkCanvas*, const gfx::Rect&) = 0;
+  virtual void PaintBackButtonStart(SkCanvas*, const gfx::Rect&) = 0;
+  virtual void PaintBackButtonEnd(SkCanvas*, const gfx::Rect&) = 0;
+  virtual void PaintForwardButtonStart(SkCanvas*, const gfx::Rect&) = 0;
+  virtual void PaintForwardButtonEnd(SkCanvas*, const gfx::Rect&) = 0;
+  virtual void PaintTickmarks(SkCanvas*, const gfx::Rect&) = 0;
+  virtual void PaintThumb(SkCanvas*, const gfx::Rect&) = 0;
+};
+
+}  // namespace cc
+
+#endif  // CC_SCROLLBAR_THEME_PAINTER_H_