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

Source/core/editing/InsertParagraphSeparatorCommand.cpp

 /*
  * Copyright (C) 2005, 2006 Apple Computer, 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 63 matching lines @@
 {
     // It is only important to set a style to apply later if we're at the boundaries of
     // a paragraph. Otherwise, content that is moved as part of the work of the command
     // will lend their styles to the new paragraph without any extra work needed.
     VisiblePosition visiblePos(pos, VP_DEFAULT_AFFINITY);
     if (!isStartOfParagraph(visiblePos) && !isEndOfParagraph(visiblePos))
         return;
 
     ASSERT(pos.isNotNull());
     m_style = EditingStyle::create(pos);
-    m_style->mergeTypingStyle(pos.anchorNode()->document());
+    m_style->mergeTypingStyle(&pos.anchorNode()->document());
 }
 
 void InsertParagraphSeparatorCommand::applyStyleAfterInsertion(Node* originalEnclosingBlock)
 {
     // Not only do we break out of header tags, but we also do not preserve the typing style,
     // in order to match other browsers.
     if (originalEnclosingBlock->hasTagName(h1Tag) ||
         originalEnclosingBlock->hasTagName(h2Tag) ||
         originalEnclosingBlock->hasTagName(h3Tag) ||
         originalEnclosingBlock->hasTagName(h4Tag) ||
@@ skipping 304 matching lines @@
             if (positionAfterSplit.deprecatedNode()->isTextNode())
                 insertTextIntoNode(toText(positionAfterSplit.containerNode()), 0, nonBreakingSpaceString());
         }
     }
 
     setEndingSelection(VisibleSelection(firstPositionInNode(blockToInsert.get()), DOWNSTREAM, endingSelection().isDirectional()));
     applyStyleAfterInsertion(startBlock.get());
 }
 
 } // namespace WebCore