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

Source/core/html/HTMLFrameElementBase.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, 2008, 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 34 matching lines @@
     virtual bool canContainRangeEndPoint() const { return false; }
 
 protected:
     HTMLFrameElementBase(const QualifiedName&, Document*);
 
     bool isURLAllowed() const;
 
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
     virtual InsertionNotificationRequest insertedInto(ContainerNode*) OVERRIDE;
     virtual void didNotifySubtreeInsertions(ContainerNode*) OVERRIDE;
-    virtual void attach();
+    virtual void attach(const AttachContext& = AttachContext()) OVERRIDE;
 
 private:
     virtual bool supportsFocus() const;
     virtual void setFocus(bool) OVERRIDE;
     
     virtual bool isURLAttribute(const Attribute&) const OVERRIDE;
     virtual bool isHTMLContentAttribute(const Attribute&) const OVERRIDE;
 
     virtual bool isFrameElementBase() const { return true; }
 
     virtual bool areAuthorShadowsAllowed() const OVERRIDE { return false; }
 
     void setNameAndOpenURL();
     void openURL(bool lockBackForwardList = true);
 
     AtomicString m_URL;
     AtomicString m_frameName;
 
     ScrollbarMode m_scrolling;
 
     int m_marginWidth;
     int m_marginHeight;
 };
 
 } // namespace WebCore
 
 #endif // HTMLFrameElementBase_h