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

Source/core/editing/VisibleSelection.cpp

 /*
  * Copyright (C) 2004, 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 115 matching lines @@
     m_extent = visiblePosition.deepEquivalent();
     validate();
 }
 
 PassRefPtr<Range> VisibleSelection::firstRange() const
 {
     if (isNone())
         return 0;
     Position start = m_start.parentAnchoredEquivalent();
     Position end = m_end.parentAnchoredEquivalent();
-    return Range::create(start.anchorNode()->document(), start, end);
+    return Range::create(&start.anchorNode()->document(), start, end);
 }
 
 PassRefPtr<Range> VisibleSelection::toNormalizedRange() const
 {
     if (isNone())
         return 0;
 
     // Make sure we have an updated layout since this function is called
     // in the course of running edit commands which modify the DOM.
     // Failing to call this can result in equivalentXXXPosition calls returning
     // incorrect results.
-    m_start.anchorNode()->document()->updateLayout();
+    m_start.anchorNode()->document().updateLayout();
 
     // Check again, because updating layout can clear the selection.
     if (isNone())
         return 0;
 
     Position s, e;
     if (isCaret()) {
         // If the selection is a caret, move the range start upstream. This helps us match
         // the conventions of text editors tested, which make style determinations based
         // on the character before the caret, if any.
@@ skipping 23 matching lines @@
         }
         s = s.parentAnchoredEquivalent();
         e = e.parentAnchoredEquivalent();
     }
 
     if (!s.containerNode() || !e.containerNode())
         return 0;
 
     // VisibleSelections are supposed to always be valid.  This constructor will ASSERT
     // if a valid range could not be created, which is fine for this callsite.
-    return Range::create(s.anchorNode()->document(), s, e);
+    return Range::create(&s.anchorNode()->document(), s, e);
 }
 
 bool VisibleSelection::expandUsingGranularity(TextGranularity granularity)
 {
     if (isNone())
         return false;
 
     validate(granularity);
     return true;
 }
 
 static PassRefPtr<Range> makeSearchRange(const Position& pos)
 {
     Node* n = pos.deprecatedNode();
     if (!n)
         return 0;
-    Document* d = n->document();
-    Node* de = d->documentElement();
+    Document& d = n->document();
+    Node* de = d.documentElement();
     if (!de)
         return 0;
     Node* boundary = n->enclosingBlockFlowElement();
     if (!boundary)
         return 0;
 
-    RefPtr<Range> searchRange(Range::create(d));
+    RefPtr<Range> searchRange(Range::create(&d));
     TrackExceptionState es;
 
     Position start(pos.parentAnchoredEquivalent());
     searchRange->selectNodeContents(boundary, es);
     searchRange->setStart(start.containerNode(), start.offsetInContainerNode(), es);
 
     ASSERT(!es.hadException());
     if (es.hadException())
         return 0;
 
@@ skipping 509 matching lines @@
     sel.showTreeForThis();
 }
 
 void showTree(const WebCore::VisibleSelection* sel)
 {
     if (sel)
         sel->showTreeForThis();
 }
 
 #endif