Use refs for GraphicsContext

third_party/WebKit/Source/platform/mac/ThemeMac.h

 /*
  * Copyright (C) 2008 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 29 matching lines @@
     virtual FontDescription controlFont(ControlPart, const FontDescription&, float zoomFactor) const;
 
     virtual LengthSize controlSize(ControlPart, const FontDescription&, const LengthSize&, float zoomFactor) const;
     virtual LengthSize minimumControlSize(ControlPart, const FontDescription&, float zoomFactor) const;
 
     virtual LengthBox controlPadding(ControlPart, const FontDescription&, const LengthBox& zoomedBox, float zoomFactor) const;
     virtual LengthBox controlBorder(ControlPart, const FontDescription&, const LengthBox& zoomedBox, float zoomFactor) const;
 
     virtual bool controlRequiresPreWhiteSpace(ControlPart part) const { return part == PushButtonPart; }
 
-    virtual void paint(ControlPart, ControlStates, GraphicsContext*, const IntRect&, float zoomFactor, ScrollableArea*) const;
+    virtual void paint(ControlPart, ControlStates, GraphicsContext&, const IntRect&, float zoomFactor, ScrollableArea*) const;
     virtual void addVisualOverflow(ControlPart, ControlStates, float zoomFactor, IntRect& borderBox) const;
 
     // Inflate an IntRect to accout for specific padding around margins.
     enum {
         TopMargin = 0,
         RightMargin = 1,
         BottomMargin = 2,
         LeftMargin = 3
     };
     static PLATFORM_EXPORT IntRect inflateRect(const IntRect&, const IntSize&, const int* margins, float zoomLevel = 1.0f);
 
     // Inflate an IntRect to account for any bleeding that would happen due to anti-aliasing.
     static PLATFORM_EXPORT IntRect inflateRectForAA(const IntRect&);
 
     // Inflate an IntRect to account for its focus ring. This is only used when
     // drawWithFrameDrawsFocusRing() returns true (otherwise, the focus ring's
     // bounds could be accurately computed with -[NSCell focusRingMaskBoundsForFrame:inView:]).
     static PLATFORM_EXPORT IntRect inflateRectForFocusRing(const IntRect&);
 
     static PLATFORM_EXPORT bool drawWithFrameDrawsFocusRing();
 };
 
 } // namespace blink
 
 #endif // ThemeMac_h