Update AbstractWorker, Worker and SharedWorker to match the spec

Source/core/workers/Worker.cpp

 /*
  * Copyright (C) 2008, 2010 Apple Inc. All Rights Reserved.
  * Copyright (C) 2009 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
@@ skipping 30 matching lines @@
 #include "core/page/Frame.h"
 #include "core/page/UseCounter.h"
 #include "core/workers/WorkerContextProxy.h"
 #include "core/workers/WorkerScriptLoader.h"
 #include "core/workers/WorkerThread.h"
 #include "wtf/MainThread.h"
 
 namespace WebCore {
 
 inline Worker::Worker(ScriptExecutionContext* context)
-    : AbstractWorker(context)
+    : ActiveDOMObject(context)
     , m_contextProxy(WorkerContextProxy::create(this))
 {
     ScriptWrappable::init(this);
 }
 
 PassRefPtr<Worker> Worker::create(ScriptExecutionContext* context, const String& url, ExceptionCode& ec)
 {
     ASSERT(isMainThread());
     UseCounter::count(static_cast<Document*>(context)->domWindow(), UseCounter::WorkerStart);
 
@@ skipping 70 matching lines @@
         if (InspectorInstrumentation::shouldPauseDedicatedWorkerOnStart(scriptExecutionContext()))
             startMode = PauseWorkerContextOnStart;
         m_contextProxy->startWorkerContext(m_scriptLoader->url(), scriptExecutionContext()->userAgent(m_scriptLoader->url()), m_scriptLoader->script(), startMode);
         InspectorInstrumentation::scriptImported(scriptExecutionContext(), m_scriptLoader->identifier(), m_scriptLoader->script());
     }
     m_scriptLoader = nullptr;
 
     unsetPendingActivity(this);
 }
 
+void Worker::contextDestroyed()
+{
+    ActiveDOMObject::contextDestroyed();
+}
+
 } // namespace WebCore