ChromeOS: Fix removeUser button on signin screen.

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_USER_SELECTION_SCREEN_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_USER_SELECTION_SCREEN_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 30 matching lines @@
   void SetHandler(LoginDisplayWebUIHandler* handler);
   void SetView(UserBoardView* view);
 
   static const user_manager::UserList PrepareUserListForSending(
       const user_manager::UserList& users,
       const AccountId& owner,
       bool is_signin_to_add);
 
   virtual void Init(const user_manager::UserList& users, bool show_guest);
   void OnUserImageChanged(const user_manager::User& user);
-  void OnBeforeUserRemoved(const std::string& username);
-  void OnUserRemoved(const std::string& username);
+  void OnBeforeUserRemoved(const AccountId& account_id);
+  void OnUserRemoved(const AccountId& account_id);
 
   void OnPasswordClearTimerExpired();
 
   void HandleGetUsers();
   void CheckUserStatus(const AccountId& account_id);
 
   // ui::UserActivityDetector implementation:
   void OnUserActivity(const ui::Event* event) override;
 
   void InitEasyUnlock();
@@ skipping 83 matching lines @@
   scoped_ptr<TokenHandleUtil> token_handle_util_;
 
   base::WeakPtrFactory<UserSelectionScreen> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UserSelectionScreen);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_USER_SELECTION_SCREEN_H_