Have ElementTraversal / NodeTraversal's next() methods take a reference

Source/bindings/v8/RetainedDOMInfo.cpp

 /*
  * Copyright (C) 2011 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 63 matching lines @@
 const char* RetainedDOMInfo::GetLabel()
 {
     return m_root->inDocument() ? "Document DOM tree" : "Detached DOM tree";
 }
 
 intptr_t RetainedDOMInfo::GetElementCount()
 {
     intptr_t count = 1;
     Node* current = m_root;
     while (current) {
-        current = NodeTraversal::next(current, m_root);
+        current = NodeTraversal::next(*current, m_root);
         ++count;
     }
     return count;
 }
 
 intptr_t RetainedDOMInfo::GetEquivalenceClass()
 {
     return reinterpret_cast<intptr_t>(m_root);
 }
 
 } // namespace WebCore