Use refs for GraphicsContext

third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp

 /*
  * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * 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 412 matching lines @@
         RefPtr<SkImage> image = sourceImage->imageForCurrentFrame();
         for (CanvasDrawListener* listener : m_listeners) {
             if (listener->needsNewFrame()) {
                 listener->sendNewFrame(image);
             }
         }
     }
 
 }
 
-void HTMLCanvasElement::paint(GraphicsContext* context, const LayoutRect& r)
+void HTMLCanvasElement::paint(GraphicsContext& context, const LayoutRect& r)
 {
     // FIXME: crbug.com/438240; there is a bug with the new CSS blending and compositing feature.
     if (!m_context)
         return;
     if (!paintsIntoCanvasBuffer() && !document().printing())
         return;
 
     m_context->paintRenderingResultsToCanvas(FrontBuffer);
     if (hasImageBuffer()) {
-        if (!context->contextDisabled()) {
+        if (!context.contextDisabled()) {
             SkXfermode::Mode compositeOperator = !m_context || m_context->hasAlpha() ? SkXfermode::kSrcOver_Mode : SkXfermode::kSrc_Mode;
             buffer()->draw(context, pixelSnappedIntRect(r), 0, compositeOperator);
         }
     } else {
         // When alpha is false, we should draw to opaque black.
         if (!m_context->hasAlpha())
-            context->fillRect(FloatRect(r), Color(0, 0, 0));
+            context.fillRect(FloatRect(r), Color(0, 0, 0));
     }
 
     if (is3D() && paintsIntoCanvasBuffer())
         m_context->markLayerComposited();
 }
 
 bool HTMLCanvasElement::is3D() const
 {
     return m_context && m_context->is3d();
 }
@@ skipping 530 matching lines @@
     }
     return ImageBitmapSource::fulfillImageBitmap(scriptState, isPaintable() ? ImageBitmap::create(this, IntRect(sx, sy, sw, sh)) : nullptr);
 }
 
 bool HTMLCanvasElement::isOpaque() const
 {
     return m_context && !m_context->hasAlpha();
 }
 
 } // blink