workers: Move ownership of WebThread from WorkerThread

Source/core/workers/WorkerThread.cpp

 /*
  * Copyright (C) 2008 Apple 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 247 matching lines @@
 
 WorkerThread::WorkerThread(const char* threadName, PassRefPtr<WorkerLoaderProxy> workerLoaderProxy, WorkerReportingProxy& workerReportingProxy, PassOwnPtr<WorkerThreadStartupData> startupData)
     : m_threadName(threadName)
     , m_terminated(false)
     , m_workerLoaderProxy(workerLoaderProxy)
     , m_workerReportingProxy(workerReportingProxy)
     , m_startupData(startupData)
     , m_isolate(nullptr)
     , m_shutdownEvent(adoptPtr(blink::Platform::current()->createWaitableEvent()))
     , m_terminationEvent(adoptPtr(blink::Platform::current()->createWaitableEvent()))
+    , m_thread(nullptr)
 {
     MutexLocker lock(threadSetMutex());
     workerThreads().add(this);
 }
 
 WorkerThread::~WorkerThread()
 {
     MutexLocker lock(threadSetMutex());
     ASSERT(workerThreads().contains(this));
     workerThreads().remove(this);
 }
 
 void WorkerThread::start()
 {
     if (m_thread)
         return;
-
-    m_thread = createWebThreadSupportingGC();
+    m_thread = m_startupData->m_thread;
+    if (!m_thread) {
+        m_ownThread = createWebThreadSupportingGC();
+        m_thread = m_ownThread.get();
+    }
     m_thread->postTask(FROM_HERE, new Task(threadSafeBind(&WorkerThread::initialize, AllowCrossThreadAccess(this))));
 }
 
 void WorkerThread::interruptAndDispatchInspectorCommands()
 {
     MutexLocker locker(m_workerInspectorControllerMutex);
     if (m_workerInspectorController)
         m_workerInspectorController->interruptAndDispatchInspectorCommands();
 }
 
@@ skipping 315 matching lines @@
     InspectorInstrumentation::didLeaveNestedRunLoop(m_workerGlobalScope.get());
 }
 
 void WorkerThread::setWorkerInspectorController(WorkerInspectorController* workerInspectorController)
 {
     MutexLocker locker(m_workerInspectorControllerMutex);
     m_workerInspectorController = workerInspectorController;
 }
 
 } // namespace blink