Implement select listbox using shadow DOM

Source/core/html/HTMLSelectElement.h

Index: Source/core/html/HTMLSelectElement.h
diff --git a/Source/core/html/HTMLSelectElement.h b/Source/core/html/HTMLSelectElement.h
index 77049422066b0de12d13e1d720a00d4609979270..54ef63aa97eab936a21f955d5b529129214a076e 100644
--- a/Source/core/html/HTMLSelectElement.h
+++ b/Source/core/html/HTMLSelectElement.h
@@ -26,6 +26,7 @@
 #ifndef HTMLSelectElement_h
 #define HTMLSelectElement_h
 
+#include "core/html/HTMLContentElement.h"
 #include "core/html/HTMLFormControlElementWithState.h"
 #include "core/html/HTMLOptionsCollection.h"
 #include "core/html/forms/TypeAhead.h"
@@ -33,8 +34,10 @@
 
 namespace WebCore {
 
+class AutoscrollController;
 class ExceptionState;
 class HTMLOptionElement;
+class MouseEvent;
 
 class HTMLSelectElement FINAL : public HTMLFormControlElementWithState, public TypeAheadDataSource {
 public:
@@ -97,6 +100,7 @@ public:
     Element* item(unsigned index);
 
     void scrollToSelection();
+    void scrollTo(int listIndex);
 
     void listBoxSelectItem(int listIndex, bool allowMultiplySelections, bool shift, bool fireOnChangeNow = true);
 
@@ -113,6 +117,7 @@ public:
 
     // For use in the implementation of HTMLOptionElement.
     void optionSelectionStateChanged(HTMLOptionElement*, bool optionIsSelected);
+    void optionRemoved(HTMLOptionElement*);
     bool anonymousIndexedSetter(unsigned, PassRefPtrWillBeRawPtr<HTMLOptionElement>, ExceptionState&);
 
     void updateListOnRenderer();
@@ -145,6 +150,7 @@ private:
 
     virtual RenderObject* createRenderer(RenderStyle*) OVERRIDE;
     virtual bool appendFormData(FormDataList&, bool) OVERRIDE;
+    virtual void didAddUserAgentShadowRoot(ShadowRoot&) OVERRIDE;
 
     virtual void defaultEventHandler(Event*) OVERRIDE;
 
@@ -189,6 +195,9 @@ private:
     int firstSelectableListIndex() const;
     int lastSelectableListIndex() const;
     int nextSelectableListIndexPageAway(int startIndex, SkipDirection) const;
+    int listIndexForEventTargetOption(const Event&);
+    int listIndexForOption(const HTMLOptionElement&);
+    AutoscrollController* autoscrollController() const;
 
     virtual void childrenChanged(bool changedByParser = false, Node* beforeChange = 0, Node* afterChange = 0, int childCountDelta = 0) OVERRIDE;
     virtual bool areAuthorShadowsAllowed() const OVERRIDE { return false; }