Fix HTMLDocumentParser::stopBackgroundParser crash

third_party/WebKit/Source/core/html/parser/HTMLDocumentParser.cpp

 /*
  * 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 111 matching lines @@
     , m_shouldUseThreading(syncPolicy == AllowAsynchronousParsing)
     , m_endWasDelayed(false)
     , m_haveBackgroundParser(false)
     , m_tasksWereSuspended(false)
     , m_pumpSessionNestingLevel(0)
     , m_pumpSpeculationsSessionNestingLevel(0)
     , m_isParsingAtLineNumber(false)
     , m_triedLoadingLinkHeaders(false)
 {
     ASSERT(shouldUseThreading() || (m_token && m_tokenizer));
+    ThreadState::current()->registerPreFinalizer(this);
 }
 
 HTMLDocumentParser::~HTMLDocumentParser()
 {
+}
+
+void HTMLDocumentParser::dispose()
+{
     // In Oilpan, HTMLDocumentParser can die together with Document, and
     // detach() is not called in this case.
     if (m_haveBackgroundParser)
         stopBackgroundParser();
 }
 
 DEFINE_TRACE(HTMLDocumentParser)
 {
     visitor->trace(m_treeBuilder);
     visitor->trace(m_parserScheduler);
@@ skipping 568 matching lines @@
 }
 
 void HTMLDocumentParser::startBackgroundParser()
 {
     ASSERT(!isStopped());
     ASSERT(shouldUseThreading());
     ASSERT(!m_haveBackgroundParser);
     ASSERT(document());
     m_haveBackgroundParser = true;
 
+    // TODO(alexclarke): Remove WebFrameScheduler::setDocumentParsingInBackground when background parser goes away.
     if (document()->frame() && document()->frame()->frameScheduler())
         document()->frame()->frameScheduler()->setDocumentParsingInBackground(true);
 
     // Make sure that a resolver is set up, so that the correct viewport dimensions will be fed to the background parser and preload scanner.
     if (document()->loader())
         document()->ensureStyleResolver();
 
     RefPtr<WeakReference<BackgroundHTMLParser>> reference = WeakReference<BackgroundHTMLParser>::createUnbound();
     m_backgroundParser = WeakPtr<BackgroundHTMLParser>(reference);
 
@@ skipping 429 matching lines @@
         (*WTF::bind(function, std::forward<Ps>(parameters)...))();
         return;
     case Asynchronous:
         m_loadingTaskRunner->postTask(BLINK_FROM_HERE, WTF::bind(function, std::forward<Ps>(parameters)...));
         return;
     }
     NOTREACHED();
 }
 
 } // namespace blink