Revert of ChromeOS login webui refactoring: split user selection/gaia login screens.

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

-// Copyright (c) 2012 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 <string>
-
-#include "base/bind.h"
-#include "base/compiler_specific.h"
-#include "chrome/browser/chromeos/login/users/user.h"
-
-namespace chromeos {
-
-class LoginDisplayWebUIHandler;
-
-// This class represents User Selection screen: user pod-based login screen.
-class UserSelectionScreen {
- public:
-  UserSelectionScreen();
-  virtual ~UserSelectionScreen();
-
-  void SetHandler(LoginDisplayWebUIHandler* handler);
-
-  void Init(const UserList& users);
-  const UserList& GetUsers() const;
-  void OnUserImageChanged(const User& user);
-  void OnBeforeUserRemoved(const std::string& username);
-  void OnUserRemoved(const std::string& username);
-
- private:
-  LoginDisplayWebUIHandler* handler_;
-
-  // Set of Users that are visible.
-  UserList users_;
-
-  DISALLOW_COPY_AND_ASSIGN(UserSelectionScreen);
-};
-
-}  // namespace chromeos
-
-#endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_USER_SELECTION_SCREEN_H_