introduce DocumentParserClient to receive parser stopped notification

Source/core/dom/DocumentParser.h

 /*
  * Copyright (C) 2000 Peter Kelly (pmk@post.com)
  * Copyright (C) 2005, 2006 Apple Computer, Inc.
  * Copyright (C) 2007 Samuel Weinig (sam@webkit.org)
  * Copyright (C) 2010 Google, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 13 matching lines @@
 #ifndef DocumentParser_h
 #define DocumentParser_h
 
 #include "platform/heap/Handle.h"
 #include "wtf/Forward.h"
 #include "wtf/RefCounted.h"
 
 namespace blink {
 
 class Document;
+class DocumentParserClient;
 class SegmentedString;
 class ScriptableDocumentParser;
 class TextResourceDecoder;
 
 class DocumentParser : public RefCountedWillBeGarbageCollectedFinalized<DocumentParser> {
 public:
     virtual ~DocumentParser();
     virtual void trace(Visitor*);
 
     virtual ScriptableDocumentParser* asScriptableDocumentParser() { return 0; }
@@ skipping 52 matching lines @@
     // Oilpan: We don't need to call detach when a Document is destructed.
     virtual void detach();
 
     void setDocumentWasLoadedAsPartOfNavigation() { m_documentWasLoadedAsPartOfNavigation = true; }
     bool documentWasLoadedAsPartOfNavigation() const { return m_documentWasLoadedAsPartOfNavigation; }
 
     // FIXME: The names are not very accurate :(
     virtual void suspendScheduledTasks();
     virtual void resumeScheduledTasks();
 
+    void addClient(DocumentParserClient*);
+    void removeClient(DocumentParserClient*);
+
 protected:
     explicit DocumentParser(Document*);
 
     virtual void flush() = 0;
 
 private:
     enum ParserState {
         ParsingState,
         StoppingState,
         StoppedState,
         DetachedState
     };
     ParserState m_state;
     bool m_documentWasLoadedAsPartOfNavigation;
 
     // Every DocumentParser needs a pointer back to the document.
     // m_document will be 0 after the parser is stopped.
     RawPtrWillBeMember<Document> m_document;
+
+    WillBeHeapHashSet<RawPtrWillBeMember<DocumentParserClient> > m_clients;
 };
 
 } // namespace blink
 
 #endif // DocumentParser_h