ChromeOS: This CL fixes bug in UserManager::GetKnownUserAccountId .

chrome/browser/chromeos/login/screens/user_selection_screen.h

Index: chrome/browser/chromeos/login/screens/user_selection_screen.h
diff --git a/chrome/browser/chromeos/login/screens/user_selection_screen.h b/chrome/browser/chromeos/login/screens/user_selection_screen.h
index 71dcb9903dee65832341158281980e66a139d835..8cf1edc7df44a9b27f1736d3c55a07481bdfc7da 100644
--- a/chrome/browser/chromeos/login/screens/user_selection_screen.h
+++ b/chrome/browser/chromeos/login/screens/user_selection_screen.h
@@ -109,10 +109,6 @@ class UserSelectionScreen
   static bool ShouldForceOnlineSignIn(const user_manager::User* user);
 
  protected:
-  // This call forms full account id of a known user by email.
-  // This is a temporary call while migrating to AccountId.
-  static AccountId GetAccountIdOfKnownUser(const std::string& user_id);
-
   LoginDisplayWebUIHandler* handler_;
   LoginDisplay::Delegate* login_display_delegate_;
   UserBoardView* view_;