:hover style not applied on hover if its display property is different from original style's

Source/core/html/HTMLFrameElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  * Copyright (C) 2004, 2006, 2009 Apple 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 21 matching lines @@
 public:
     static PassRefPtr<HTMLFrameElement> create(const QualifiedName&, Document*);
 
     bool hasFrameBorder() const { return m_frameBorder; }
 
     bool noResize() const;
 
 private:
     HTMLFrameElement(const QualifiedName&, Document*);
 
-    virtual void attach();
+    virtual void attach(const AttachContext& = AttachContext()) OVERRIDE;
 
     virtual bool rendererIsNeeded(const NodeRenderingContext&);
     virtual RenderObject* createRenderer(RenderArena*, RenderStyle*);
     
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
 
     virtual bool allowFullScreen() const { return false; }
 
     bool m_frameBorder;
     bool m_frameBorderSet;
 };
 
 } // namespace WebCore
 
 #endif // HTMLFrameElement_h