Revert "Extract ContextLifecycleNotifier from ScriptExecutionContext."

Source/modules/webdatabase/DatabaseContext.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 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 113 matching lines @@
 }
 
 // This is called if the associated ScriptExecutionContext is destructing while
 // we're still associated with it. That's our cue to disassociate and shutdown.
 // To do this, we stop the database and let everything shutdown naturally
 // because the database closing process may still make use of this context.
 // It is not safe to just delete the context here.
 void DatabaseContext::contextDestroyed()
 {
     stopDatabases();
-    ActiveDOMObject::contextDestroyed();
+
+    // Normally, willDestroyActiveDOMObject() is called in ~ActiveDOMObject().
+    // However, we're here because the destructor hasn't been called, and the
+    // ScriptExecutionContext we're associated with is about to be destructed.
+    // So, go ahead an unregister self from the ActiveDOMObject list, and
+    // set m_scriptExecutionContext to 0 so that ~ActiveDOMObject() doesn't
+    // try to do so again.
+    m_scriptExecutionContext->willDestroyActiveDOMObject(this);
+    m_scriptExecutionContext = 0;
 }
 
 // stop() is from stopActiveDOMObjects() which indicates that the owner Frame
 // or WorkerThread is shutting down. Initiate the orderly shutdown by stopping
 // the associated databases.
 void DatabaseContext::stop()
 {
     stopDatabases();
 }
 
@@ skipping 52 matching lines @@
     if (m_scriptExecutionContext->isDocument()) {
         Document* document = toDocument(m_scriptExecutionContext);
         return document->page();
     }
     ASSERT(m_scriptExecutionContext->isWorkerContext());
     // allowDatabaseAccess is not yet implemented for workers.
     return true;
 }
 
 } // namespace WebCore