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

Source/core/editing/Caret.cpp

 /*
  * Copyright (C) 2004, 2008, 2009, 2010 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 52 matching lines @@
 
 void DragCaretController::setCaretPosition(const VisiblePosition& position)
 {
     if (Node* node = m_position.deepEquivalent().deprecatedNode())
         invalidateCaretRect(node);
     m_position = position;
     setCaretRectNeedsUpdate();
     Document* document = 0;
     if (Node* node = m_position.deepEquivalent().deprecatedNode()) {
         invalidateCaretRect(node);
-        document = node->document();
+        document = &node->document();
     }
     if (m_position.isNull() || m_position.isOrphan())
         clearCaretRect();
     else
         updateCaretRect(document, m_position);
 }
 
 static bool removingNodeRemovesPosition(Node* node, const Position& position)
 {
     if (!position.anchorNode())
         return false;
 
     if (position.anchorNode() == node)
         return true;
 
     if (!node->isElementNode())
         return false;
 
     Element* element = toElement(node);
     return element->containsIncludingShadowDOM(position.anchorNode());
 }
 
 static void clearRenderViewSelection(const Position& position)
 {
-    RefPtr<Document> document = position.anchorNode()->document();
+    RefPtr<Document> document = &position.anchorNode()->document();
     document->updateStyleIfNeeded();
     if (RenderView* view = document->renderView())
         view->clearSelection();
 }
 
 void DragCaretController::nodeWillBeRemoved(Node* node)
 {
     if (!hasCaret() || (node && !node->inDocument()))
         return;
 
@@ skipping 116 matching lines @@
     // that we try to paint the caret after this call. That one will work since
     // it happens after the document has accounted for any editing
     // changes which may have been done.
     // And, we need to leave this layout here so the caret moves right
     // away after clicking.
     m_caretRectNeedsUpdate = true;
 
     if (caretRectChanged)
         return;
 
-    if (RenderView* view = node->document()->renderView()) {
+    if (RenderView* view = node->document().renderView()) {
         if (shouldRepaintCaret(view, node->isContentEditable(Node::UserSelectAllIsAlwaysNonEditable)))
             repaintCaretForLocalRect(node, localCaretRectWithoutUpdate());
     }
 }
 
 void CaretBase::paintCaret(Node* node, GraphicsContext* context, const LayoutPoint& paintOffset, const LayoutRect& clipRect) const
 {
     if (m_caretVisibility == Hidden)
         return;
 
@@ skipping 15 matching lines @@
         element = node->parentElement();
 
     if (element && element->renderer())
         caretColor = element->renderer()->resolveColor(CSSPropertyColor);
 
     context->fillRect(caret, caretColor);
 }
 
 void DragCaretController::paintDragCaret(Frame* frame, GraphicsContext* p, const LayoutPoint& paintOffset, const LayoutRect& clipRect) const
 {
-    if (m_position.deepEquivalent().deprecatedNode()->document()->frame() == frame)
+    if (m_position.deepEquivalent().deprecatedNode()->document().frame() == frame)
         paintCaret(m_position.deepEquivalent().deprecatedNode(), p, paintOffset, clipRect);
 }
 
 }