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

Source/core/rendering/RenderListBox.h

Index: Source/core/rendering/RenderListBox.h
diff --git a/Source/core/rendering/RenderListBox.h b/Source/core/rendering/RenderListBox.h
index efc47aa25103ee9bf7341490fa9a87f8ec049003..ded1f7ab8b029947ce41d7c8c087f73a640765ff 100644
--- a/Source/core/rendering/RenderListBox.h
+++ b/Source/core/rendering/RenderListBox.h
@@ -47,17 +47,17 @@ public:
 
     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;
@@ -139,6 +139,7 @@ private:
 
     LayoutUnit itemHeight() const;
     int numVisibleItems() const;
+    bool listIndexIsVisible(int index) const;
     int numItems() const;
     LayoutUnit listHeight() const;
     int scrollbarLeft() const;
@@ -147,11 +148,14 @@ private:
     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;
 };