Oilpan: Replace RefPtrs to Node and its subclasses in core/testing with Oilpan transition types.

Source/core/testing/MockPagePopupDriver.cpp

 /*
  * Copyright (C) 2012 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:
  *
  * 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 33 matching lines @@
     static PassRefPtr<MockPagePopup> create(PagePopupClient*, const IntRect& originBoundsInRootView, LocalFrame*);
     virtual ~MockPagePopup();
     bool initialize();
     void closeLater();
 
 private:
     MockPagePopup(PagePopupClient*, const IntRect& originBoundsInRootView, LocalFrame*);
     void close(Timer<MockPagePopup>*);
 
     PagePopupClient* m_popupClient;
-    RefPtr<HTMLIFrameElement> m_iframe;
+    RefPtrWillBePersistent<HTMLIFrameElement> m_iframe;
     Timer<MockPagePopup> m_closeTimer;
 };
 
 inline MockPagePopup::MockPagePopup(PagePopupClient* client, const IntRect& originBoundsInRootView, LocalFrame* mainFrame)
     : m_popupClient(client)
     , m_closeTimer(this, &MockPagePopup::close)
 {
     Document* document = mainFrame->document();
     ASSERT(document);
     m_iframe = HTMLIFrameElement::create(*document);
@@ skipping 78 matching lines @@
 {
     if (!popup || popup != m_mockPagePopup.get())
         return;
     m_mockPagePopup->closeLater();
     m_mockPagePopup.clear();
     m_pagePopupController->clearPagePopupClient();
     m_pagePopupController.clear();
 }
 
 }