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

Source/core/dom/Document.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 478 matching lines @@
     bool isPageBoxVisible(int pageIndex);
 
     // Returns the preferred page size and margins in pixels, assuming 96
     // pixels per inch. pageSize, marginTop, marginRight, marginBottom,
     // marginLeft must be initialized to the default values that are used if
     // auto is specified.
     void pageSizeAndMarginsInPixels(int pageIndex, IntSize& pageSize, int& marginTop, int& marginRight, int& marginBottom, int& marginLeft);
 
     CachedResourceLoader* cachedResourceLoader() { return m_cachedResourceLoader.get(); }
 
-    virtual void attach();
-    virtual void detach();
+    virtual void attach(const AttachContext& = AttachContext()) OVERRIDE;
+    virtual void detach(const AttachContext& = AttachContext()) OVERRIDE;
     void prepareForDestruction();
 
     // Override ScriptExecutionContext methods to do additional work
     virtual void suspendActiveDOMObjects(ActiveDOMObject::ReasonForSuspension) OVERRIDE;
     virtual void resumeActiveDOMObjects() OVERRIDE;
 
     RenderArena* renderArena() { return m_renderArena.get(); }
 
     // Implemented in RenderView.h to avoid a cyclic header dependency this just
     // returns renderer so callers can avoid verbose casts.
@@ skipping 978 matching lines @@
 inline bool Node::isDocumentNode() const
 {
     return this == documentInternal();
 }
 
 Node* eventTargetNodeForDocument(Document*);
 
 } // namespace WebCore
 
 #endif // Document_h