Oilpan: Use transition types for HTMLDivElement.

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 793 matching lines @@
         // If cue has an empty text track cue region identifier or there is no
         // WebVTT region whose region identifier is identical to cue's text
         // track cue region identifier, run the following substeps:
         if (displayBox->hasChildren() && !container.contains(displayBox.get())) {
             // Note: the display tree of a cue is removed when the active flag of the cue is unset.
             container.appendChild(displayBox);
         }
     } else {
         // Let region be the WebVTT region whose region identifier
         // matches the text track cue region identifier of cue.
-        RefPtr<HTMLDivElement> regionNode = region->getDisplayTree(document());
+        RefPtrWillBeRawPtr<HTMLDivElement> regionNode = region->getDisplayTree(document());
 
         // Append the region to the viewport, if it was not already.
         if (!container.contains(regionNode.get()))
             container.appendChild(regionNode);
 
         region->appendVTTCueBox(displayBox);
     }
 }
 
 std::pair<double, double> VTTCue::getPositionCoordinates() const
@@ skipping 273 matching lines @@
 
 void VTTCue::trace(Visitor* visitor)
 {
     visitor->trace(m_vttNodeTree);
     visitor->trace(m_cueBackgroundBox);
     visitor->trace(m_displayTree);
     TextTrackCue::trace(visitor);
 }
 
 } // namespace WebCore