cros: Change max users to be a constant

ash/common/session/session_controller.h

 // Copyright 2016 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 ASH_COMMON_SESSION_SESSION_CONTROLLER_H_
 #define ASH_COMMON_SESSION_SESSION_CONTROLLER_H_
 
 #include <stdint.h>
 
 #include <vector>
@@ skipping 85 matching lines @@
   void SetSessionState(session_manager::SessionState state);
   void AddUserSession(mojom::UserSessionPtr user_session);
 
   // Bindings for mojom::SessionController interface.
   mojo::BindingSet<mojom::SessionController> bindings_;
 
   // Client interface to session manager code (chrome).
   mojom::SessionControllerClientPtr client_;
 
   // Cached session info.
-  uint32_t max_users_ = 0u;
   bool can_lock_ = false;
   bool should_lock_screen_automatically_ = false;
   AddUserSessionPolicy add_user_session_policy_ = AddUserSessionPolicy::ALLOWED;
   session_manager::SessionState state_ = session_manager::SessionState::UNKNOWN;
 
   // Cached user session info sorted by the order from SetUserSessionOrder.
   // Currently the session manager code (chrome) sets a LRU order with the
   // active session being the first.
   std::vector<mojom::UserSessionPtr> user_sessions_;
 
   // The user session id of the current active user session. User session id
   // is managed by session manager code, starting at 1. 0u is an invalid id
   // to detect first active user session.
   uint32_t active_session_id_ = 0u;
 
   base::ObserverList<ash::SessionStateObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(SessionController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SESSION_SESSION_CONTROLLER_H_