Clean up forward declarations in Source/modules

Source/modules/quota/StorageQuota.h

 /*
  * Copyright (C) 2014 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 20 matching lines @@
 #ifndef StorageQuota_h
 #define StorageQuota_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Forward.h"
 
 namespace blink {
 
-class ExecutionContext;
-
 class StorageQuota final : public GarbageCollected<StorageQuota>, public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
     static StorageQuota* create()
     {
         return new StorageQuota();
     }
 
     Vector<String> supportedTypes() const;
 
     ScriptPromise queryInfo(ScriptState*, String type);
     ScriptPromise requestPersistentQuota(ScriptState*, unsigned long long newQuota);
 
     void trace(Visitor*) { }
 
 private:
     StorageQuota();
 };
 
 } // namespace blink
 
 #endif // StorageQuota_h