ash: Refresh the tray items, instead of recreating them, when login status changes.

ash/system/ime/tray_ime.cc

Index: ash/system/ime/tray_ime.cc
diff --git a/ash/system/ime/tray_ime.cc b/ash/system/ime/tray_ime.cc
index 40767c019e55bfc2d5a8f814578bdda9482973f3..15a9d80f1a7ad75654778d47b028b90d8c17e955 100644
--- a/ash/system/ime/tray_ime.cc
+++ b/ash/system/ime/tray_ime.cc
@@ -229,6 +229,9 @@ void TrayIME::DestroyDetailedView() {
   detailed_.reset();
 }
 
+void TrayIME::UpdateAfterLoginStatusChange(user::LoginStatus status) {
+}
+
 void TrayIME::OnIMERefresh() {
   SystemTrayDelegate* delegate = Shell::GetInstance()->tray_delegate();
   IMEInfoList list;