DOMDataStore should be cleared when shutting down worker threads

Source/core/events/ErrorEvent.cpp

 /*
  * 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:
  *
  *     * 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 42 matching lines @@
     : Event(type, initializer)
     , m_sanitizedMessage(initializer.message)
     , m_fileName(initializer.filename)
     , m_lineNumber(initializer.lineno)
     , m_columnNumber(initializer.colno)
     , m_world(DOMWrapperWorld::current(v8::Isolate::GetCurrent()))
 {
     ScriptWrappable::init(this);
 }
 
-ErrorEvent::ErrorEvent(const String& message, const String& fileName, unsigned lineNumber, unsigned columnNumber, PassRefPtr<DOMWrapperWorld> world)
+ErrorEvent::ErrorEvent(const String& message, const String& fileName, unsigned lineNumber, unsigned columnNumber, DOMWrapperWorld* world)
     : Event(EventTypeNames::error, false, true)
     , m_sanitizedMessage(message)
     , m_fileName(fileName)
     , m_lineNumber(lineNumber)
     , m_columnNumber(columnNumber)
     , m_world(world)
 {
     ScriptWrappable::init(this);
 }
 
@@ skipping 11 matching lines @@
 {
     return EventNames::ErrorEvent;
 }
 
 void ErrorEvent::trace(Visitor* visitor)
 {
     Event::trace(visitor);
 }
 
 } // namespace WebCore