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

Source/core/editing/RemoveNodeCommand.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 15 matching lines @@
 #include "config.h"
 #include "core/editing/RemoveNodeCommand.h"
 
 #include "bindings/v8/ExceptionStatePlaceholder.h"
 #include "core/dom/Node.h"
 #include "wtf/Assertions.h"
 
 namespace WebCore {
 
 RemoveNodeCommand::RemoveNodeCommand(PassRefPtr<Node> node, ShouldAssumeContentIsAlwaysEditable shouldAssumeContentIsAlwaysEditable)
-    : SimpleEditCommand(node->document())
+    : SimpleEditCommand(&node->document())
     , m_node(node)
     , m_shouldAssumeContentIsAlwaysEditable(shouldAssumeContentIsAlwaysEditable)
 {
     ASSERT(m_node);
     ASSERT(m_node->parentNode());
 }
 
 void RemoveNodeCommand::doApply()
 {
     ContainerNode* parent = m_node->parentNode();
@@ skipping 21 matching lines @@
 #ifndef NDEBUG
 void RemoveNodeCommand::getNodesInCommand(HashSet<Node*>& nodes)
 {
     addNodeAndDescendants(m_parent.get(), nodes);
     addNodeAndDescendants(m_refChild.get(), nodes);
     addNodeAndDescendants(m_node.get(), nodes);
 }
 #endif
 
 }