Oilpan: Make ActiveParserSession::m_document traceable.

Source/core/html/parser/HTMLParserScheduler.h

 /*
  * Copyright (C) 2010 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 20 matching lines @@
 #include "wtf/CurrentTime.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/RefPtr.h"
 
 namespace WebCore {
 
 class Document;
 class HTMLDocumentParser;
 
 class ActiveParserSession {
+    STACK_ALLOCATED();
 public:
     explicit ActiveParserSession(Document*);
     ~ActiveParserSession();
 
 private:
-    RefPtr<Document> m_document;
+    RefPtrWillBeMember<Document> m_document;
 };
 
 class PumpSession : public NestingLevelIncrementer, public ActiveParserSession {
+    STACK_ALLOCATED();
 public:
     PumpSession(unsigned& nestingLevel, Document*);
     ~PumpSession();
 
     int processedTokens;
     double startTime;
     bool needsYield;
     bool didSeeScript;
 };
 
@@ skipping 41 matching lines @@
 
     HTMLDocumentParser* m_parser;
 
     Timer<HTMLParserScheduler> m_continueNextChunkTimer;
     bool m_isSuspendedWithActiveTimer;
 };
 
 }
 
 #endif