Use refs for GraphicsContext

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

 /*
  * Copyright (c) 2008, Google Inc. All rights reserved.
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * 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:
  *
  *     * Redistributions of source code must retain the above copyright
@@ skipping 233 matching lines @@
     Platform3DObject textureId = m_surface->getBackingTextureHandleForOverwrite();
     if (!textureId)
         return false;
 
     context3D->flush();
 
     return drawingBuffer->copyToPlatformTexture(context3D, textureId, GL_RGBA,
         GL_UNSIGNED_BYTE, 0, true, false, sourceBuffer);
 }
 
-void ImageBuffer::draw(GraphicsContext* context, const FloatRect& destRect, const FloatRect* srcPtr, SkXfermode::Mode op)
+void ImageBuffer::draw(GraphicsContext& context, const FloatRect& destRect, const FloatRect* srcPtr, SkXfermode::Mode op)
 {
     if (!isSurfaceValid())
         return;
 
     FloatRect srcRect = srcPtr ? *srcPtr : FloatRect(FloatPoint(), FloatSize(size()));
     m_surface->draw(context, destRect, srcRect, op);
 }
 
 void ImageBuffer::flush()
 {
@@ skipping 106 matching lines @@
     ASSERT(MIMETypeRegistry::isSupportedImageMIMETypeForEncoding(mimeType));
 
     Vector<unsigned char> result;
     if (!encodeImage(mimeType, quality, &result))
         return "data:,";
 
     return "data:" + mimeType + ";base64," + base64Encode(result);
 }
 
 } // namespace blink