Oilpan: Replace RefPtrs to Node and its subclasses in core/html with Oilpan transitin types.

Source/core/html/track/vtt/VTTCue.cpp

 /*
  * Copyright (c) 2013, Opera Software ASA. 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 406 matching lines @@
 
 void VTTCue::createVTTNodeTree()
 {
     if (!m_vttNodeTree)
         m_vttNodeTree = VTTParser::createDocumentFragmentFromCueText(document(), m_text);
 }
 
 void VTTCue::copyVTTNodeToDOMTree(ContainerNode* vttNode, ContainerNode* parent)
 {
     for (Node* node = vttNode->firstChild(); node; node = node->nextSibling()) {
-        RefPtr<Node> clonedNode;
+        RefPtrWillBeRawPtr<Node> clonedNode;
         if (node->isVTTElement())
             clonedNode = toVTTElement(node)->createEquivalentHTMLElement(document());
         else
             clonedNode = node->cloneNode(false);
         parent->appendChild(clonedNode);
         if (node->isContainerNode())
             copyVTTNodeToDOMTree(toContainerNode(node), toContainerNode(clonedNode));
     }
 }
 
@@ skipping 660 matching lines @@
 
 void VTTCue::trace(Visitor* visitor)
 {
     visitor->trace(m_vttNodeTree);
     visitor->trace(m_cueBackgroundBox);
     visitor->trace(m_displayTree);
     TextTrackCue::trace(visitor);
 }
 
 } // namespace WebCore