ash: Use enum for SessionController::CycleActiveUser

ash/public/interfaces/session_controller.mojom

 // 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.
 
 module ash.mojom;
 
 import "components/signin/public/interfaces/account_id.mojom";
 import "skia/public/interfaces/bitmap.mojom";
 
 // Matches session_manager::SessionState.
@@ skipping 47 matching lines @@
   // Child user, with supervised options.
   CHILD,
 
   // Android app in kiosk mode, logs in without authentication.
   ARC_KIOSK,
 
   // Active Directory user. Authenticates against Active Directory server.
   ACTIVE_DIRECTORY,
 };
 
+// Matches ash::CycleUserDirection.
+enum CycleUserDirection {
+  NEXT,  // Cycle to the next user.
+  PREVIOUS,  // Cycle to the previous user.
+};
+
 // Info about a user session in ash.
 struct UserSession {
   // A user session id for the user session. It is generated by session manager
   // (chrome) when a user session starts and never changes during the lifetime
   // of the session manager. The number starts at 1 for the first user session
   // and incremented by one for each subsequent user session.
   uint32 session_id;
 
   UserType type;
   signin.mojom.AccountId account_id;
@@ skipping 55 matching lines @@
 // Interface for ash to request session service from its client (e.g. Chrome).
 interface SessionControllerClient {
   // Requests to lock screen.
   RequestLockScreen();
 
   // Switch to the active user with |account_id| (if the user has already signed
   // in).
   SwitchActiveUser(signin.mojom.AccountId account_id);
 
   // Switch the active user to the next or previous user.
-  CycleActiveUser(bool next_user);
+  CycleActiveUser(CycleUserDirection direction);
 };