ash: Use enum for SessionController::CycleActiveUser

ash/common/test/test_session_state_delegate.cc

 // Copyright (c) 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.
 
 #include "ash/common/test/test_session_state_delegate.h"
 
 #include <algorithm>
 #include <string>
 
 #include "ash/common/login_status.h"
@@ skipping 216 matching lines @@
   active_user_index_ = 0;
   for (auto iter = user_list_.begin(); iter != user_list_.end(); ++iter) {
     if ((*iter)->GetAccountId() == account_id) {
       active_user_index_ = iter - user_list_.begin();
       return;
     }
   }
   NOTREACHED() << "Unknown user:" << account_id.GetUserEmail();
 }
 
-void TestSessionStateDelegate::CycleActiveUser(CycleUser cycle_user) {
+void TestSessionStateDelegate::CycleActiveUser(CycleUserDirection direction) {
   SwitchActiveUser(AccountId::FromUserEmail("someone@tray"));
 }
 
 bool TestSessionStateDelegate::IsMultiProfileAllowedByPrimaryUserPolicy()
     const {
   return true;
 }
 
 void TestSessionStateDelegate::AddSessionStateObserver(
     SessionStateObserver* observer) {}
 
 void TestSessionStateDelegate::RemoveSessionStateObserver(
     SessionStateObserver* observer) {}
 
 }  // namespace test
 }  // namespace ash