Implement select element list box with shadow DOM.

Source/WebCore/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 160 matching lines @@
     enum SkipDirection {
         SkipBackwards = -1,
         SkipForwards = 1
     };
     int nextValidIndex(int listIndex, SkipDirection, int skip) const;
     int nextSelectableListIndex(int startIndex) const;
     int previousSelectableListIndex(int startIndex) const;
     int firstSelectableListIndex() const;
     int lastSelectableListIndex() const;
     int nextSelectableListIndexPageAway(int startIndex, SkipDirection) const;
+    int listIndexForEvent(Event*);
 
     virtual void childrenChanged(bool changedByParser = false, Node* beforeChange = 0, Node* afterChange = 0, int childCountDelta = 0);
     virtual bool areAuthorShadowsAllowed() const OVERRIDE { return false; }
 
     // TypeAheadDataSource functions.
     virtual int indexOfSelectedOption() const OVERRIDE;
     virtual int optionCount() const OVERRIDE;
     virtual String optionAtIndex(int index) const OVERRIDE;
 
     // m_listItems contains HTMLOptionElement, HTMLOptGroupElement, and HTMLHRElement objects.
@@ skipping 26 matching lines @@
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!node || isHTMLSelectElement(node));
     return static_cast<const HTMLSelectElement*>(node);
 }
 
 void toHTMLSelectElement(const HTMLSelectElement*); // This overload will catch anyone doing an unnecessary cast.
 
 } // namespace
 
 #endif