Remove owned views from AXAuraObjCache when widget is deleted.

ui/views/accessibility/ax_aura_obj_cache.h

Index: ui/views/accessibility/ax_aura_obj_cache.h
diff --git a/ui/views/accessibility/ax_aura_obj_cache.h b/ui/views/accessibility/ax_aura_obj_cache.h
index f3e35a65cb702879411139a4382003702d090342..81384a177d93d4efe6d849438f65f43af37b4ff5 100644
--- a/ui/views/accessibility/ax_aura_obj_cache.h
+++ b/ui/views/accessibility/ax_aura_obj_cache.h
@@ -47,6 +47,9 @@ class VIEWS_EXPORT AXAuraObjCache {
   void Remove(Widget* widget);
   void Remove(aura::Window* window);
 
+  // Removes a view and all of its descendants from the cache.
+  void RemoveViewSubtree(View* view);
+
   // Lookup a cached entry based on an id.
   AXAuraObjWrapper* Get(int32 id);