Hide notification tray when the user flow doesn't allow

ash/common/system/web_notification/web_notification_tray.cc

Index: ash/common/system/web_notification/web_notification_tray.cc
diff --git a/ash/common/system/web_notification/web_notification_tray.cc b/ash/common/system/web_notification/web_notification_tray.cc
index 351fd4412253ed8c436a48b3afd157b2f7cc0923..b6814039a77f344028998afda57d9a4733093c54 100644
--- a/ash/common/system/web_notification/web_notification_tray.cc
+++ b/ash/common/system/web_notification/web_notification_tray.cc
@@ -636,7 +636,7 @@ void WebNotificationTray::UpdateTrayContent() {
     counter_->SetVisible(false);
   }
 
-  SetVisible(IsLoggedIn());
+  SetVisible(IsLoggedIn() && ShouldShowMessageCenter());
   PreferredSizeChanged();
   Layout();
   SchedulePaint();