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

cc/scrollbar_theme_painter.h

Index: cc/scrollbar_theme_painter.h
diff --git a/cc/scrollbar_theme_painter.h b/cc/scrollbar_theme_painter.h
new file mode 100644
index 0000000000000000000000000000000000000000..4053eb7026ecfc1998f9d58c63936c8f8f73f38e
--- /dev/null
+++ b/cc/scrollbar_theme_painter.h
@@ -0,0 +1,36 @@
+// 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_