Implement computedRole and computedName (behind a flag)

Source/modules/accessibility/AXListBox.h

Index: Source/modules/accessibility/AXListBox.h
diff --git a/Source/modules/accessibility/AXListBox.h b/Source/modules/accessibility/AXListBox.h
index f28a00c9e738c5088d1f19773e6575f036420ed3..0b20e507289c32eb36dc6060a7cdef5f9ddd47da 100644
--- a/Source/modules/accessibility/AXListBox.h
+++ b/Source/modules/accessibility/AXListBox.h
@@ -33,12 +33,15 @@
 
 namespace blink {
 
+class AXObjectCache;
+
 class AXListBox final : public AXRenderObject {
 
 private:
-    explicit AXListBox(RenderObject*);
+    AXListBox(RenderObject*, AXObjectCache*);
+
 public:
-    static PassRefPtr<AXListBox> create(RenderObject*);
+    static PassRefPtr<AXListBox> create(RenderObject*, AXObjectCache*);
     virtual ~AXListBox();
 
     virtual AccessibilityRole roleValue() const override { return ListBoxRole; }