Use refs for GraphicsContext

third_party/WebKit/Source/platform/graphics/ImageBuffer.h

 /*
  * Copyright (C) 2006 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 111 matching lines @@
     bool copyRenderingResultsFromDrawingBuffer(DrawingBuffer*, SourceDrawingBuffer);
 
     void flush(); // process deferred draw commands immediately
     void flushGpu(); // Like flush(), but flushes all the way down to the Gpu context if the surface is accelerated
 
     void notifySurfaceInvalid();
 
     PassRefPtr<SkImage> newSkImageSnapshot(AccelerationHint) const;
     PassRefPtr<Image> newImageSnapshot(AccelerationHint = PreferNoAcceleration) const;
 
-    void draw(GraphicsContext*, const FloatRect&, const FloatRect*, SkXfermode::Mode);
+    void draw(GraphicsContext&, const FloatRect&, const FloatRect*, SkXfermode::Mode);
 
 private:
     ImageBuffer(PassOwnPtr<ImageBufferSurface>);
 
     enum SnapshotState {
         InitialSnapshotState,
         DidAcquireSnapshot,
         DrawnToAfterSnapshot,
     };
     mutable SnapshotState m_snapshotState;
@@ skipping 10 matching lines @@
     int height() const { return m_size.height(); }
     int width() const { return m_size.width(); }
 
     const unsigned char* m_data;
     const IntSize m_size;
 };
 
 } // namespace blink
 
 #endif // ImageBuffer_h