Use refs for GraphicsContext

third_party/WebKit/Source/platform/graphics/ImageBufferSurface.cpp

 /*
  * Copyright (c) 2013, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 52 matching lines @@
     if (isValid()) {
         if (m_opacityMode == Opaque) {
             canvas()->clear(SK_ColorBLACK);
         } else {
             canvas()->clear(SK_ColorTRANSPARENT);
         }
         didDraw(FloatRect(FloatPoint(0, 0), FloatSize(size())));
     }
 }
 
-void ImageBufferSurface::draw(GraphicsContext* context, const FloatRect& destRect, const FloatRect& srcRect, SkXfermode::Mode op)
+void ImageBufferSurface::draw(GraphicsContext& context, const FloatRect& destRect, const FloatRect& srcRect, SkXfermode::Mode op)
 {
     RefPtr<SkImage> snapshot = newImageSnapshot(PreferNoAcceleration);
     if (!snapshot)
         return;
 
     RefPtr<Image> image = StaticBitmapImage::create(snapshot.release());
-    context->drawImage(image.get(), destRect, srcRect, op);
+    context.drawImage(image.get(), destRect, srcRect, op);
 }
 
 void ImageBufferSurface::flush()
 {
     canvas()->flush();
 }
 
 bool ImageBufferSurface::writePixels(const SkImageInfo& origInfo, const void* pixels, size_t rowBytes, int x, int y)
 {
     return canvas()->writePixels(origInfo, pixels, rowBytes, x, y);
 }
 
 } // namespace blink