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

chrome/browser/chromeos/login/existing_user_controller.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_EXISTING_USER_CONTROLLER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_EXISTING_USER_CONTROLLER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/callback_forward.h"
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string16.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "chrome/browser/chromeos/app_mode/kiosk_app_manager.h"
 #include "chrome/browser/chromeos/login/session/user_session_manager.h"
 #include "chrome/browser/chromeos/login/ui/login_display.h"
 #include "chrome/browser/chromeos/settings/cros_settings.h"
 #include "chrome/browser/chromeos/settings/device_settings_service.h"
 #include "chromeos/login/auth/login_performer.h"
 #include "chromeos/login/auth/user_context.h"
 #include "components/user_manager/user.h"
+#include "components/user_manager/user_id.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "ui/gfx/geometry/rect.h"
 #include "url/gurl.h"
 
 namespace base {
 class ListValue;
 }
 
 namespace chromeos {
@@ skipping 88 matching lines @@
   bool password_changed() const;
 
  private:
   friend class ExistingUserControllerTest;
   friend class ExistingUserControllerAutoLoginTest;
   friend class ExistingUserControllerPublicSessionTest;
   friend class MockLoginPerformerDelegate;
 
   void LoginAsGuest();
   void LoginAsPublicSession(const UserContext& user_context);
-  void LoginAsKioskApp(const std::string& app_id, bool diagnostic_mode);
+  void LoginAsKioskApp(const user_manager::UserID& user_id, bool diagnostic_mode);
 
   // Retrieve public session auto-login policy and update the timer.
   void ConfigurePublicSessionAutoLogin();
 
   // Trigger public session auto-login.
   void OnPublicSessionAutoLoginTimerFire();
 
   // LoginPerformer::Delegate implementation:
   void OnAuthFailure(const AuthFailure& error) override;
   void OnAuthSuccess(const UserContext& user_context) override;
   void OnOffTheRecordAuthSuccess() override;
   void OnPasswordChangeDetected() override;
-  void WhiteListCheckFailed(const std::string& email) override;
+  void WhiteListCheckFailed(const user_manager::UserID& user_id) override;
   void PolicyLoadFailed() override;
-  void OnOnlineChecked(const std::string& username, bool success) override;
+  void OnOnlineChecked(const user_manager::UserID& user_id, bool success) override;
 
   // UserSessionManagerDelegate implementation:
   void OnProfilePrepared(Profile* profile, bool browser_launched) override;
 
   // Called when device settings change.
   void DeviceSettingsChanged();
 
   // Returns corresponding native window.
   gfx::NativeWindow GetNativeWindow() const;
 
   // Show error message. |error_id| error message ID in resources.
   // If |details| string is not empty, it specify additional error text
   // provided by authenticator, it is not localized.
   void ShowError(int error_id, const std::string& details);
 
   // Shows Gaia page because password change was detected.
-  void ShowGaiaPasswordChanged(const std::string& username);
+  void ShowGaiaPasswordChanged(const user_manager::UserID& user_id);
 
   // Handles result of ownership check and starts enterprise or kiosk enrollment
   // if applicable.
   void OnEnrollmentOwnershipCheckCompleted(
       DeviceSettingsService::OwnershipStatus status);
 
   // Handles result of consumer kiosk configurability check and starts
   // enable kiosk screen if applicable.
   void OnConsumerKioskAutoLaunchCheckCompleted(
       KioskAppManager::ConsumerKioskAutoLaunchStatus status);
@@ skipping 63 matching lines @@
 
   // Callback invoked when |oauth2_token_initializer_| has finished.
   void OnOAuth2TokensFetched(bool success, const UserContext& user_context);
 
   // Public session auto-login timer.
   scoped_ptr<base::OneShotTimer<ExistingUserController> > auto_login_timer_;
 
   // Public session auto-login timeout, in milliseconds.
   int public_session_auto_login_delay_;
 
-  // Username for public session auto-login.
-  std::string public_session_auto_login_username_;
+  // User id for public session auto-login.
+  user_manager::UserID public_session_auto_login_user_id_;
 
   // Used to execute login operations.
   scoped_ptr<LoginPerformer> login_performer_;
 
   // Delegate to forward all authentication status events to.
   // Tests can use this to receive authentication status events.
   AuthStatusConsumer* auth_status_consumer_;
 
   // Username of the last login attempt.
-  std::string last_login_attempt_username_;
+  user_manager::UserID last_login_attempt_user_id_;
 
   // OOBE/login display host.
   LoginDisplayHost* host_;
 
   // Login UI implementation instance.
   scoped_ptr<LoginDisplay> login_display_;
 
   // Number of login attempts. Used to show help link when > 1 unsuccessful
   // logins for the same user.
   size_t num_login_attempts_;
@@ skipping 14 matching lines @@
   // The displayed email for the next login attempt set by |SetDisplayEmail|.
   std::string display_email_;
 
   // Whether offline login attempt failed.
   bool offline_failed_;
 
   // Whether login attempt is running.
   bool is_login_in_progress_;
 
   // Whether online login attempt succeeded.
-  std::string online_succeeded_for_;
+  user_manager::UserID online_succeeded_for_;
 
   // True if password has been changed for user who is completing sign in.
   // Set in OnLoginSuccess. Before that use LoginPerformer::password_changed().
   bool password_changed_;
 
   // Set in OnLoginSuccess. Before that use LoginPerformer::auth_mode().
   // Initialized with AUTH_MODE_EXTENSION as more restricted mode.
   LoginPerformer::AuthorizationMode auth_mode_;
   // Whether the sign-in UI is finished loading.
   bool signin_screen_ready_;
@@ skipping 27 matching lines @@
 
   // Factory of callbacks.
   base::WeakPtrFactory<ExistingUserController> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ExistingUserController);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_EXISTING_USER_CONTROLLER_H_