Creating supervised users restricted for regular users if they are supervised.

chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc

Index: chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc
index 2b3460675dadfdc06e1a8d920e3665a7561885dd..f9841247dabf3cef23dcdaf5a0daa6ca56c78fb8 100644
--- a/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc
@@ -75,6 +75,12 @@ void UpdateAuthParams(base::DictionaryValue* params,
     supervised_users_can_create = false;
     message_id = IDS_CREATE_SUPERVISED_USER_CREATION_RESTRICTED_TEXT;
   }
+  if (supervised_users_can_create &&
+      user_manager::UserManager::Get()->
+          GetUsersAllowedForSupervisedUsersCreation().empty()) {
+     supervised_users_can_create = false;
+     message_id = IDS_CREATE_SUPERVISED_USER_NO_MANAGER_EXCEPT_SUPERVISED_TEXT;
+  }
 
   params->SetBoolean("supervisedUsersEnabled", supervised_users_allowed);
   params->SetBoolean("supervisedUsersCanCreate", supervised_users_can_create);