Use reference for FillLayer if possible

Source/core/rendering/RenderObject.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 657 matching lines @@
     void setIsBox() { m_bitfields.setIsBox(true); }
     void setReplaced(bool isReplaced) { m_bitfields.setIsReplaced(isReplaced); }
     void setHorizontalWritingMode(bool hasHorizontalWritingMode) { m_bitfields.setHorizontalWritingMode(hasHorizontalWritingMode); }
     void setHasOverflowClip(bool hasOverflowClip) { m_bitfields.setHasOverflowClip(hasOverflowClip); }
     void setHasLayer(bool hasLayer) { m_bitfields.setHasLayer(hasLayer); }
     void setHasTransform(bool hasTransform) { m_bitfields.setHasTransform(hasTransform); }
     void setHasReflection(bool hasReflection) { m_bitfields.setHasReflection(hasReflection); }
 
     void scheduleRelayout();
 
-    void updateFillImages(const FillLayer*, const FillLayer*);
+    void updateFillImages(const FillLayer* oldLayers, const FillLayer& newLayers);
     void updateImage(StyleImage*, StyleImage*);
     void updateShapeImage(const ShapeValue*, const ShapeValue*);
 
     virtual void paint(PaintInfo&, const LayoutPoint&);
 
     // Subclasses must reimplement this method to compute the size and position
     // of this object and all its descendants.
     virtual void layout() = 0;
     virtual bool updateImageLoadingPriorities() { return false; }
     void setHasPendingResourceUpdate(bool hasPendingResourceUpdate) { m_bitfields.setHasPendingResourceUpdate(hasPendingResourceUpdate); }
@@ skipping 805 matching lines @@
 void showTree(const WebCore::RenderObject*);
 void showLineTree(const WebCore::RenderObject*);
 void showRenderTree(const WebCore::RenderObject* object1);
 // We don't make object2 an optional parameter so that showRenderTree
 // can be called from gdb easily.
 void showRenderTree(const WebCore::RenderObject* object1, const WebCore::RenderObject* object2);
 
 #endif
 
 #endif // RenderObject_h