Remove retail mode.

components/user_manager/user_type.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 COMPONENTS_USER_MANAGER_USER_TYPE_H_
 #define COMPONENTS_USER_MANAGER_USER_TYPE_H_
 
 namespace user_manager {
 
 // The user type. Used in a histogram; do not modify existing types.
 typedef enum {
   // Regular user, has a user name and password.
   USER_TYPE_REGULAR = 0,
   // Guest user, logs in without authentication.
   USER_TYPE_GUEST = 1,
-  // Retail mode user, logs in without authentication. This is a special user
-  // type used in retail mode only.
-  USER_TYPE_RETAIL_MODE = 2,
+  /* USER_TYPE_RETAIL_MODE = 2, // deprecated */
   // Public account user, logs in without authentication. Available only if
   // enabled through policy.
   USER_TYPE_PUBLIC_ACCOUNT = 3,
   // Supervised user, logs in only with local authentication.
   USER_TYPE_SUPERVISED = 4,
   // Kiosk app robot, logs in without authentication.
   USER_TYPE_KIOSK_APP = 5,
   // Maximum histogram value.
   NUM_USER_TYPES = 6
 } UserType;
 
 }  // namespace user_manager
 
 #endif  // COMPONENTS_USER_MANAGER_USER_TYPE_H_