DOMDataStore should be cleared when shutting down worker threads

Source/core/workers/WorkerMessagingProxy.cpp

 /*
  * Copyright (C) 2008 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 147 matching lines @@
 }
 
 void WorkerMessagingProxy::reportException(const String& errorMessage, int lineNumber, int columnNumber, const String& sourceURL)
 {
     if (!m_workerObject)
         return;
 
     // We don't bother checking the askedToTerminate() flag here, because exceptions should *always* be reported even if the thread is terminated.
     // This is intentionally different than the behavior in MessageWorkerTask, because terminated workers no longer deliver messages (section 4.6 of the WebWorker spec), but they do report exceptions.
 
-    RefPtr<ErrorEvent> event = ErrorEvent::create(errorMessage, sourceURL, lineNumber, columnNumber, nullptr);
+    RefPtr<ErrorEvent> event = ErrorEvent::create(errorMessage, sourceURL, lineNumber, columnNumber, 0);
     bool errorHandled = !m_workerObject->dispatchEvent(event);
     if (!errorHandled)
         m_executionContext->reportException(event, nullptr, NotSharableCrossOrigin);
 }
 
 void WorkerMessagingProxy::reportConsoleMessage(MessageSource source, MessageLevel level, const String& message, int lineNumber, const String& sourceURL)
 {
     if (m_askedToTerminate)
         return;
     m_executionContext->addConsoleMessage(source, level, message, sourceURL, lineNumber);
@@ skipping 117 matching lines @@
 {
     m_workerThreadHadPendingActivity = hasPendingActivity;
 }
 
 bool WorkerMessagingProxy::hasPendingActivity() const
 {
     return (m_unconfirmedMessageCount || m_workerThreadHadPendingActivity) && !m_askedToTerminate;
 }
 
 } // namespace WebCore