Clean up forward declarations in Source/core/html

Source/core/html/HTMLSelectElement.h

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 19 matching lines @@
 #include "core/html/HTMLFormControlElementWithState.h"
 #include "core/html/HTMLOptionsCollection.h"
 #include "core/html/forms/TypeAhead.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
 class AutoscrollController;
 class ExceptionState;
 class HTMLOptionElement;
-class MouseEvent;
 
 class HTMLSelectElement FINAL : public HTMLFormControlElementWithState, public TypeAheadDataSource {
     DEFINE_WRAPPERTYPEINFO();
 public:
     static PassRefPtrWillBeRawPtr<HTMLSelectElement> create(Document&);
     static PassRefPtrWillBeRawPtr<HTMLSelectElement> create(Document&, HTMLFormElement*);
 
     int selectedIndex() const;
     void setSelectedIndex(int);
     int suggestedIndex() const;
@@ skipping 175 matching lines @@
     bool m_isProcessingUserDrivenChange;
     bool m_multiple;
     bool m_activeSelectionState;
     mutable bool m_shouldRecalcListItems;
     int m_suggestedIndex;
 };
 
 } // namespace blink
 
 #endif // HTMLSelectElement_h