blink: Cleanup class/struct forward declarations

third_party/WebKit/Source/modules/storage/DOMWindowStorageController.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef DOMWindowStorageController_h
 #define DOMWindowStorageController_h
 
 #include "core/dom/Document.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "modules/ModulesExport.h"
 #include "platform/Supplementable.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class Document;
-class Event;
 
 class MODULES_EXPORT DOMWindowStorageController final
     : public GarbageCollected<DOMWindowStorageController>,
       public Supplement<Document>,
       public LocalDOMWindow::EventListenerObserver {
   USING_GARBAGE_COLLECTED_MIXIN(DOMWindowStorageController);
 
  public:
   DECLARE_VIRTUAL_TRACE();
 
@@ skipping 10 matching lines @@
 
  private:
   Document& document() const { return *m_document; }
 
   Member<Document> m_document;
 };
 
 }  // namespace blink
 
 #endif  // DOMWindowStorageController_h