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

Source/core/css/CSSCrossfadeValue.cpp

Index: Source/core/css/CSSCrossfadeValue.cpp
diff --git a/Source/core/css/CSSCrossfadeValue.cpp b/Source/core/css/CSSCrossfadeValue.cpp
index d409f79aafabcedaeb09b51f9c18dd400214bf66..b45f6cc5d19f7c26dadfd8443493d5e4cc76ce5d 100644
--- a/Source/core/css/CSSCrossfadeValue.cpp
+++ b/Source/core/css/CSSCrossfadeValue.cpp
@@ -111,7 +111,7 @@ 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);
 
@@ -170,7 +170,7 @@ PassRefPtr<Image> CSSCrossfadeValue::image(RenderObject* renderer, const IntSize
     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);