This CL replaces e-mail with AccountId in wallpaper manager code.

chrome/browser/chromeos/login/app_launch_signin_screen.h

 // Copyright 2013 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_APP_LAUNCH_SIGNIN_SCREEN_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_APP_LAUNCH_SIGNIN_SCREEN_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 41 matching lines @@
   user_manager::UserManager* GetUserManager();
   const user_manager::UserList& GetUsers() const;
 
   // SigninScreenHandlerDelegate implementation:
   void CancelPasswordChangedFlow() override;
   void CancelUserAdding() override;
   void CompleteLogin(const UserContext& user_context) override;
   void Login(const UserContext& user_context,
              const SigninSpecifics& specifics) override;
   void MigrateUserData(const std::string& old_password) override;
-  void LoadWallpaper(const std::string& username) override;
+  void LoadWallpaper(const AccountId& account_id) override;
   void LoadSigninWallpaper() override;
   void OnSigninScreenReady() override;
   void RemoveUser(const AccountId& account_id) override;
   void ResyncUserData() override;
   void ShowEnterpriseEnrollmentScreen() override;
   void ShowEnableDebuggingScreen() override;
   void ShowKioskEnableScreen() override;
   void ShowKioskAutolaunchScreen() override;
   void ShowWrongHWIDScreen() override;
   void SetWebUIHandler(LoginDisplayWebUIHandler* webui_handler) override;
@@ skipping 22 matching lines @@
   user_manager::UserList owner_user_list_;
 
   static user_manager::UserManager* test_user_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(AppLaunchSigninScreen);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_APP_LAUNCH_SIGNIN_SCREEN_H_