Automation should fire focus event on root view of widgets

ui/views/accessibility/ax_aura_obj_cache.cc

Index: ui/views/accessibility/ax_aura_obj_cache.cc
diff --git a/ui/views/accessibility/ax_aura_obj_cache.cc b/ui/views/accessibility/ax_aura_obj_cache.cc
index 0f47bb4b6742da17c34388ba638704d09f288c93..11516c5f64be381f79863ce4021d55e9a13bc7e8 100644
--- a/ui/views/accessibility/ax_aura_obj_cache.cc
+++ b/ui/views/accessibility/ax_aura_obj_cache.cc
@@ -151,7 +151,11 @@ View* AXAuraObjCache::GetFocusedView() {
   if (!focus_manager)
     return nullptr;
 
-  return focus_manager->GetFocusedView();
+  View* focused_view = focus_manager->GetFocusedView();
+  if (focused_view)
+    return focused_view;
+  else
+    return focused_widget->GetRootView();
 }
 
 void AXAuraObjCache::OnWindowFocused(aura::Window* gained_focus,