Oilpan: Trace VTTParser::m_document.

Source/core/html/track/vtt/VTTParser.h

 /*
  * 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 95 matching lines @@
 
     // Transfers ownership of last parsed cues to caller.
     void getNewCues(WillBeHeapVector<RefPtrWillBeMember<VTTCue> >&);
     void getNewRegions(WillBeHeapVector<RefPtrWillBeMember<VTTRegion> >&);
 
     void trace(Visitor*);
 
 private:
     VTTParser(VTTParserClient*, Document&);
 
-    Document* m_document;
+    RawPtrWillBeMember<Document> m_document;
     ParseState m_state;
 
     void parse();
     void flushPendingCue();
     bool hasRequiredFileIdentifier(const String& line);
     ParseState collectCueId(const String&);
     ParseState collectTimingsAndSettings(const String&);
     ParseState collectCueText(const String&);
     ParseState recoverCue(const String&);
     ParseState ignoreBadCue(const String&);
@@ skipping 17 matching lines @@
     VTTParserClient* m_client;
 
     WillBeHeapVector<RefPtrWillBeMember<VTTCue> > m_cueList;
 
     WillBeHeapVector<RefPtrWillBeMember<VTTRegion> > m_regionList;
 };
 
 } // namespace WebCore
 
 #endif