Removed unregisterTerminationObserver from DatabaseContext::contextDestroyed

Source/core/workers/WorkerGlobalScope.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2009, 2011 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 185 matching lines @@
     m_workerInspectorController.clear();
 }
 
 void WorkerGlobalScope::registerTerminationObserver(TerminationObserver* observer)
 {
     ASSERT(!m_terminationObserver);
     ASSERT(observer);
     m_terminationObserver = observer;
 }
 
-void WorkerGlobalScope::unregisterTerminationObserver(TerminationObserver* observer)
-{
-    ASSERT(observer);
-    ASSERT(m_terminationObserver == observer);
-    m_terminationObserver = 0;
-}
-
 void WorkerGlobalScope::wasRequestedToTerminate()
 {
     if (m_terminationObserver)
         m_terminationObserver->wasRequestedToTerminate();
 }
 
 void WorkerGlobalScope::dispose()
 {
     ASSERT(thread()->isCurrentThread());
 
@@ skipping 130 matching lines @@
     visitor->trace(m_workerInspectorController);
     visitor->trace(m_eventQueue);
     visitor->trace(m_workerClients);
     visitor->trace(m_messageStorage);
     WillBeHeapSupplementable<WorkerGlobalScope>::trace(visitor);
     ExecutionContext::trace(visitor);
     EventTargetWithInlineData::trace(visitor);
 }
 
 } // namespace blink