Implement WebThreadSupportingGC, which wraps a WebThread attached to Oilpan's GC

Source/core/html/parser/HTMLParserThread.cpp

 /*
  * Copyright (C) 2013 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 38 matching lines @@
 }
 
 void HTMLParserThread::init()
 {
     ASSERT(!s_sharedThread);
     s_sharedThread = new HTMLParserThread;
 }
 
 void HTMLParserThread::setupHTMLParserThread()
 {
-    m_pendingGCRunner = adoptPtr(new PendingGCRunner);
-    m_messageLoopInterruptor = adoptPtr(new MessageLoopInterruptor(&platformThread()));
-    platformThread().addTaskObserver(m_pendingGCRunner.get());
-    ThreadState::attach();
-    ThreadState::current()->addInterruptor(m_messageLoopInterruptor.get());
+    ASSERT(m_thread);
+    m_thread->attachGC();
 }
 
 void HTMLParserThread::shutdown()
 {
     ASSERT(s_sharedThread);
     // currentThread will always be non-null in production, but can be null in Chromium unit tests.
     if (blink::Platform::current()->currentThread() && s_sharedThread->isRunning()) {
         TaskSynchronizer taskSynchronizer;
         s_sharedThread->postTask(WTF::bind(&HTMLParserThread::cleanupHTMLParserThread, s_sharedThread, &taskSynchronizer));
         taskSynchronizer.waitForTaskCompletion();
     }
     delete s_sharedThread;
     s_sharedThread = 0;
 }
 
 void HTMLParserThread::cleanupHTMLParserThread(TaskSynchronizer* taskSynchronizer)
 {
-    ThreadState::current()->removeInterruptor(m_messageLoopInterruptor.get());
-    ThreadState::detach();
-    platformThread().removeTaskObserver(m_pendingGCRunner.get());
-    m_pendingGCRunner = nullptr;
-    m_messageLoopInterruptor = nullptr;
+    m_thread->detachGC();
     taskSynchronizer->taskCompleted();
 }
 
 HTMLParserThread* HTMLParserThread::shared()
 {
     return s_sharedThread;
 }
 
 blink::WebThread& HTMLParserThread::platformThread()
 {
     if (!isRunning()) {
-        m_thread = adoptPtr(blink::Platform::current()->createThread("HTMLParserThread"));
+        m_thread = WebThreadRunner::create("HTMLParserThread");
         postTask(WTF::bind(&HTMLParserThread::setupHTMLParserThread, this));
     }
-    return *m_thread;
+    return m_thread->platformThread();
 }
 
 bool HTMLParserThread::isRunning()
 {
     return !!m_thread;
 }
 
 void HTMLParserThread::postTask(const Closure& closure)
 {
     platformThread().postTask(new Task(closure));
 }
 
 } // namespace blink