Use refs for GraphicsContext

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.h

 /*
  * Copyright (C) 2009, 2010, 2011 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 281 matching lines @@
 
     Color layoutObjectBackgroundColor() const;
     void updateBackgroundColor();
     void updateContentsRect();
     void updateContentsOffsetInCompositingLayer(const IntPoint& snappedOffsetFromCompositedAncestor, const IntPoint& graphicsLayerParentLocation);
     void updateAfterPartResize();
     void updateCompositingReasons();
 
     static bool hasVisibleNonCompositingDescendant(PaintLayer* parent);
 
-    void doPaintTask(const GraphicsLayerPaintInfo&, const GraphicsLayer&, const PaintLayerFlags&, GraphicsContext*, const IntRect& clip) const;
+    void doPaintTask(const GraphicsLayerPaintInfo&, const GraphicsLayer&, const PaintLayerFlags&, GraphicsContext&, const IntRect& clip) const;
 
     // Computes the background clip rect for the given squashed layer, up to any containing layer that is squashed into the
     // same squashing layer and contains this squashed layer's clipping ancestor.
     // The clip rect is returned in the coordinate space of the given squashed layer.
     // If there is no such containing layer, returns the infinite rect.
     // FIXME: unify this code with the code that sets up m_ancestorClippingLayer. They are doing very similar things.
     static IntRect localClipRectForSquashedLayer(const PaintLayer& referenceLayer, const GraphicsLayerPaintInfo&,  const Vector<GraphicsLayerPaintInfo>& layers);
 
     // Return true if |m_owningLayer|'s compositing ancestor is not a descendant (inclusive) of the
     // clipping container for |m_owningLayer|.
@@ skipping 128 matching lines @@
 
     unsigned m_backgroundLayerPaintsFixedRootBackground : 1;
     unsigned m_scrollingContentsAreEmpty : 1;
 
     friend class CompositedLayerMappingTest;
 };
 
 } // namespace blink
 
 #endif // CompositedLayerMapping_h