Update AbstractWorker, Worker and SharedWorker to match the spec

Source/core/workers/SharedWorker.h

Index: Source/core/workers/SharedWorker.h
diff --git a/Source/core/workers/SharedWorker.h b/Source/core/workers/SharedWorker.h
index 859c0c67a8799177dc87a93a6dcf35691f402f43..06e5b0314bdbe915c54d5768a9111ad87c00b87e 100644
--- a/Source/core/workers/SharedWorker.h
+++ b/Source/core/workers/SharedWorker.h
@@ -32,11 +32,12 @@
 #ifndef SharedWorker_h
 #define SharedWorker_h
 
+#include "core/dom/ActiveDOMObject.h"
 #include "core/workers/AbstractWorker.h"
 
 namespace WebCore {
 
-    class SharedWorker : public AbstractWorker {
+    class SharedWorker : public AbstractWorker, public ScriptWrappable, public ActiveDOMObject {
     public:
         static PassRefPtr<SharedWorker> create(ScriptExecutionContext*, const String& url, const String& name, ExceptionCode&);
         virtual ~SharedWorker();
@@ -44,6 +45,8 @@ namespace WebCore {
         MessagePort* port() const { return m_port.get(); }
 
         virtual const AtomicString& interfaceName() const OVERRIDE;
+        virtual void contextDestroyed() OVERRIDE;
+        virtual ScriptExecutionContext* scriptExecutionContext() const OVERRIDE { return ActiveDOMObject::scriptExecutionContext(); }
 
     private:
         explicit SharedWorker(ScriptExecutionContext*);