Add skia::RefPtr class to wrap ref counted classes from Skia.

skia/ext/vector_canvas.h

 // Copyright (c) 2011 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 SKIA_EXT_VECTOR_CANVAS_H_
 #define SKIA_EXT_VECTOR_CANVAS_H_
 
 #include "base/compiler_specific.h"
 #include "skia/ext/platform_canvas.h"
+#include "skia/ext/refptr.h"
 
 class SkDevice;
 
 namespace skia {
 
 // This class is a specialization of the regular PlatformCanvas. It is designed
 // to work with a VectorDevice to manage platform-specific drawing. It allows
 // using both Skia operations and platform-specific operations. It *doesn't*
 // support reading back from the bitmap backstore since it is not used.
 class SK_API VectorCanvas : public PlatformCanvas {
  public:
   // Ownership of |device| is transfered to VectorCanvas.
-  explicit VectorCanvas(SkDevice* device);
+  explicit VectorCanvas(const skia::RefPtr<SkDevice>& device);
   virtual ~VectorCanvas();
 
   virtual SkBounder* setBounder(SkBounder* bounder) OVERRIDE;
   virtual SkDrawFilter* setDrawFilter(SkDrawFilter* filter) OVERRIDE;
 
  private:
   // Returns true if the top device is vector based and not bitmap based.
   bool IsTopDeviceVectorial() const;
 
   // Copy & assign are not supported.
   VectorCanvas(const VectorCanvas&);
   const VectorCanvas& operator=(const VectorCanvas&);
 };
 
 }  // namespace skia
 
 #endif  // SKIA_EXT_VECTOR_CANVAS_H_