Update add user button dynamically after policy push

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

Index: chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
index c2e02ebf25b4c6c2d424a3f6866604709c012ac1..52dbf79df92764fee37b2f020fef7a09ef8cd4b9 100644
--- a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
@@ -1069,6 +1069,7 @@ void SigninScreenHandler::OnPreferencesChanged() {
     // has changed so that reloaded GAIA shows/hides the option to create a new
     // account.
     UpdateUIState(UI_STATE_ACCOUNT_PICKER, nullptr);
+    UpdateAddButtonStatus();
   }
 }