cros: Use SessionController for lock starting code

chrome/browser/ui/ash/session_controller_client.cc

 // 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.
 
 #include "chrome/browser/ui/ash/session_controller_client.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "ash/public/cpp/session_types.h"
@@ skipping 100 matching lines @@
   SessionManager::Get()->RemoveObserver(this);
   UserManager::Get()->RemoveObserver(this);
   UserManager::Get()->RemoveSessionStateObserver(this);
 }
 
 // static
 SessionControllerClient* SessionControllerClient::Get() {
   return g_instance;
 }
 
+void SessionControllerClient::StartLock(StartLockCallback callback) {
+  session_controller_->StartLock(callback);
+}
+
 void SessionControllerClient::RunUnlockAnimation(
     base::Closure animation_finished_callback) {
   session_controller_->RunUnlockAnimation(animation_finished_callback);
 }
 
 void SessionControllerClient::RequestLockScreen() {
   DoLockScreen();
 }
 
 void SessionControllerClient::SwitchActiveUser(const AccountId& account_id) {
@@ skipping 189 matching lines @@
   const UserList logged_in_users = user_manager->GetLoggedInUsers();
   std::vector<uint32_t> user_session_ids;
   for (auto* user : user_manager->GetLRULoggedInUsers()) {
     const uint32_t user_session_id = GetSessionId(*user);
     DCHECK_NE(0u, user_session_id);
     user_session_ids.push_back(user_session_id);
   }
 
   session_controller_->SetUserSessionOrder(user_session_ids);
 }