Update <select> when any of its <option> children has "display: none"

Source/core/rendering/RenderListBox.h

 /*
  * This file is part of the select element renderer in WebCore.
  *
  * Copyright (C) 2006, 2007, 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
@@ skipping 29 matching lines @@
 
 class RenderListBox FINAL : public RenderBlockFlow, private ScrollableArea {
 public:
     explicit RenderListBox(Element*);
     virtual ~RenderListBox();
 
     void selectionChanged();
 
     void setOptionsChanged(bool changed) { m_optionsChanged = changed; }
 
-    int listIndexAtOffset(const LayoutSize&);
-    LayoutRect itemBoundingBoxRect(const LayoutPoint&, int index);
+    int listIndexAtOffset(const LayoutSize&) const;
+    LayoutRect itemBoundingBoxRect(const LayoutPoint&, int index) const;
 
     bool scrollToRevealElementAtListIndex(int index);
-    bool listIndexIsVisible(int index);
 
     int scrollToward(const IntPoint&); // Returns the new index or -1 if no scroll occurred
 
     int size() const;
 
     void repaintScrollbarIfNeeded();
+    int toRenderListBoxIndex(int index) const;
 
 private:
     HTMLSelectElement* selectElement() const;
 
     virtual const char* renderName() const OVERRIDE { return "RenderListBox"; }
 
     virtual bool isListBox() const OVERRIDE { return true; }
     virtual bool isChildAllowed(RenderObject*, RenderStyle*) const OVERRIDE;
 
     virtual void updateFromElement() OVERRIDE;
@@ skipping 61 matching lines @@
 
     // NOTE: This should only be called by the overriden setScrollOffset from ScrollableArea.
     void scrollTo(int newOffset);
 
     void setHasVerticalScrollbar(bool hasScrollbar);
     PassRefPtr<Scrollbar> createScrollbar();
     void destroyScrollbar();
 
     LayoutUnit itemHeight() const;
     int numVisibleItems() const;
+    bool listIndexIsVisible(int index) const;
     int numItems() const;
     LayoutUnit listHeight() const;
     int scrollbarLeft() const;
     void paintScrollbar(PaintInfo&, const LayoutPoint&);
     void paintItemForeground(PaintInfo&, const LayoutPoint&, int listIndex);
     void paintItemBackground(PaintInfo&, const LayoutPoint&, int listIndex);
     void scrollToRevealSelection();
 
+    int toOptionListIndex(int index) const;
+
     bool m_optionsChanged;
     bool m_scrollToRevealSelectionAfterLayout;
     bool m_inAutoscroll;
     int m_optionsWidth;
     int m_indexOffset;
+    int m_listItemCount;
 
     RefPtr<Scrollbar> m_vBar;
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderListBox, isListBox());
 
 } // namepace WebCore
 
 #endif // RenderListBox_h