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

Source/core/editing/SplitElementCommand.cpp

 /*
  * Copyright (C) 2005, 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 17 matching lines @@
 
 #include "HTMLNames.h"
 #include "bindings/v8/ExceptionState.h"
 #include "bindings/v8/ExceptionStatePlaceholder.h"
 #include "core/dom/Element.h"
 #include "wtf/Assertions.h"
 
 namespace WebCore {
 
 SplitElementCommand::SplitElementCommand(PassRefPtr<Element> element, PassRefPtr<Node> atChild)
-    : SimpleEditCommand(element->document())
+    : SimpleEditCommand(&element->document())
     , m_element2(element)
     , m_atChild(atChild)
 {
     ASSERT(m_element2);
     ASSERT(m_atChild);
     ASSERT(m_atChild->parentNode() == m_element2);
 }
 
 void SplitElementCommand::executeApply()
 {
@@ skipping 61 matching lines @@
 #ifndef NDEBUG
 void SplitElementCommand::getNodesInCommand(HashSet<Node*>& nodes)
 {
     addNodeAndDescendants(m_element1.get(), nodes);
     addNodeAndDescendants(m_element2.get(), nodes);
     addNodeAndDescendants(m_atChild.get(), nodes);
 }
 #endif
 
 } // namespace WebCore