Clean up forward declarations in Source/modules

Source/modules/indexeddb/WorkerGlobalScopeIndexedDatabase.h

 /*
  * Copyright (C) 2008, 2009 Apple 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 14 matching lines @@
  */
 
 #ifndef WorkerGlobalScopeIndexedDatabase_h
 #define WorkerGlobalScopeIndexedDatabase_h
 
 #include "platform/Supplementable.h"
 
 namespace blink {
 
 class IDBFactory;
-class IndexedDBClient;
-class ExecutionContext;
 class WorkerGlobalScope;
 
 class WorkerGlobalScopeIndexedDatabase final : public NoBaseWillBeGarbageCollectedFinalized<WorkerGlobalScopeIndexedDatabase>, public WillBeHeapSupplement<WorkerGlobalScope> {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(WorkerGlobalScopeIndexedDatabase);
 public:
     virtual ~WorkerGlobalScopeIndexedDatabase();
     static WorkerGlobalScopeIndexedDatabase& from(WillBeHeapSupplementable<WorkerGlobalScope>&);
 
     static IDBFactory* indexedDB(WillBeHeapSupplementable<WorkerGlobalScope>&);
 
     virtual void trace(Visitor*);
 
 private:
     WorkerGlobalScopeIndexedDatabase();
 
     IDBFactory* indexedDB();
     static const char* supplementName();
 
     PersistentWillBeMember<IDBFactory> m_idbFactory;
 };
 
 } // namespace blink
 
 #endif // WorkerGlobalScopeIndexedDatabase_h