We should use UserID object to identify users instead of username.

chrome/browser/chromeos/login/easy_unlock/easy_unlock_reauth.cc

Index: chrome/browser/chromeos/login/easy_unlock/easy_unlock_reauth.cc
diff --git a/chrome/browser/chromeos/login/easy_unlock/easy_unlock_reauth.cc b/chrome/browser/chromeos/login/easy_unlock/easy_unlock_reauth.cc
index f56fbbb6b7f88ca047542b6e0fa420f6e8ea98d9..a5b7928a89171694301334a90b2ab02bd41c6763 100644
--- a/chrome/browser/chromeos/login/easy_unlock/easy_unlock_reauth.cc
+++ b/chrome/browser/chromeos/login/easy_unlock/easy_unlock_reauth.cc
@@ -86,7 +86,7 @@ class ReauthHandler : public content::NotificationObserver,
     const user_manager::UserList& lock_users = screen_locker->users();
     DCHECK(lock_users.size() == 1);
     GetScreenlockBridgeInstance()->lock_handler()->ShowUserPodCustomIcon(
-        lock_users[0]->email(), icon_options);
+        lock_users[0]->GetUserID(), icon_options);
   }
 
   // chromeos::AuthStatusConsumer: