Enable fast/images with slimming paint

Source/core/paint/HTMLCanvasClipper.h

+// Copyright 2014 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 HTMLCanvasClipper_h
+#define HTMLCanvasClipper_h
+
+#include "platform/geometry/LayoutRect.h"
+
+namespace blink {
+
+class RenderHTMLCanvas;
+struct PaintInfo;
+
+class HTMLCanvasClipper {
+public:
+    HTMLCanvasClipper(RenderHTMLCanvas&, const PaintInfo&, const LayoutRect& clipRect);
+    ~HTMLCanvasClipper();
+private:
+    LayoutRect m_clipRect;
+    const PaintInfo& m_paintInfo;
+    RenderHTMLCanvas& m_canvas;
+};
+
+} // namespace blink
+
+#endif // HTMLCanvasClipper_h