Have Node::document() return a reference instead of a pointer

Source/core/css/CSSCrossfadeValue.cpp

 /*
  * Copyright (C) 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 93 matching lines @@
     result.append(m_percentageValue->cssText());
     result.append(')');
     return result.toString();
 }
 
 IntSize CSSCrossfadeValue::fixedSize(const RenderObject* renderer)
 {
     float percentage = m_percentageValue->getFloatValue();
     float inversePercentage = 1 - percentage;
 
-    ResourceFetcher* fetcher = renderer->document()->fetcher();
+    ResourceFetcher* fetcher = renderer->document().fetcher();
     ImageResource* cachedFromImage = cachedImageForCSSValue(m_fromValue.get(), fetcher);
     ImageResource* cachedToImage = cachedImageForCSSValue(m_toValue.get(), fetcher);
 
     if (!cachedFromImage || !cachedToImage)
         return IntSize();
 
     IntSize fromImageSize = cachedFromImage->imageForRenderer(renderer)->size();
     IntSize toImageSize = cachedToImage->imageForRenderer(renderer)->size();
 
     // Rounding issues can cause transitions between images of equal size to return
@@ skipping 38 matching lines @@
     }
 
     m_crossfadeSubimageObserver.setReady(true);
 }
 
 PassRefPtr<Image> CSSCrossfadeValue::image(RenderObject* renderer, const IntSize& size)
 {
     if (size.isEmpty())
         return 0;
 
-    ResourceFetcher* fetcher = renderer->document()->fetcher();
+    ResourceFetcher* fetcher = renderer->document().fetcher();
     ImageResource* cachedFromImage = cachedImageForCSSValue(m_fromValue.get(), fetcher);
     ImageResource* cachedToImage = cachedImageForCSSValue(m_toValue.get(), fetcher);
 
     if (!cachedFromImage || !cachedToImage)
         return Image::nullImage();
 
     Image* fromImage = cachedFromImage->imageForRenderer(renderer);
     Image* toImage = cachedToImage->imageForRenderer(renderer);
 
     if (!fromImage || !toImage)
@@ skipping 29 matching lines @@
 }
 
 bool CSSCrossfadeValue::equals(const CSSCrossfadeValue& other) const
 {
     return compareCSSValuePtr(m_fromValue, other.m_fromValue)
         && compareCSSValuePtr(m_toValue, other.m_toValue)
         && compareCSSValuePtr(m_percentageValue, other.m_percentageValue);
 }
 
 } // namespace WebCore