Update focus when widget changes visibility.

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 fc9a8c91352eb1775f2bb9da12dad9c80ed56653..c73abe1ad858eddc1e5faf347e34e378a02c796f 100644
--- a/ui/views/accessibility/ax_aura_obj_cache.h
+++ b/ui/views/accessibility/ax_aura_obj_cache.h
@@ -82,6 +82,9 @@ class VIEWS_EXPORT AXAuraObjCache
   // Get the object that has focus.
   AXAuraObjWrapper* GetFocus();
 
+  // Send a notification that the focused view may have changed.
+  void OnFocusedViewChanged();
+
   // Indicates if this object's currently being destroyed.
   bool is_destroying() { return is_destroying_; }