Oilpan: Replace RefPtrs to Node and its subclasses in core/dom/ with Oilpan transtion types.

Source/core/page/DragController.cpp

 /*
  * Copyright (C) 2007, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Google Inc.
  *
  * 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
@@ skipping 153 matching lines @@
             if (!url.isEmpty()) {
                 RefPtrWillBeRawPtr<HTMLAnchorElement> anchor = HTMLAnchorElement::create(document);
                 anchor->setHref(AtomicString(url));
                 if (title.isEmpty()) {
                     // Try the plain text first because the url might be normalized or escaped.
                     if (dragData->containsPlainText())
                         title = dragData->asPlainText();
                     if (title.isEmpty())
                         title = url;
                 }
-                RefPtr<Node> anchorText = document.createTextNode(title);
-                anchor->appendChild(anchorText);
+                anchor->appendChild(document.createTextNode(title));
                 RefPtrWillBeRawPtr<DocumentFragment> fragment = document.createDocumentFragment();
                 fragment->appendChild(anchor);
                 return fragment.release();
             }
         }
     }
     if (allowPlainText && dragData->containsPlainText()) {
         chosePlainText = true;
         return createFragmentFromText(context.get(), dragData->asPlainText()).get();
     }
@@ skipping 779 matching lines @@
 
 void DragController::trace(Visitor* visitor)
 {
     visitor->trace(m_page);
     visitor->trace(m_documentUnderMouse);
     visitor->trace(m_dragInitiator);
     visitor->trace(m_fileInputElementUnderMouse);
 }
 
 } // namespace WebCore