Implement the auto-logout on idle feature for Kiosk mode.

chrome/browser/chromeos/kiosk_mode/kiosk_mode_screensaver.cc

 // Copyright (c) 2012 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/chromeos/kiosk_mode/kiosk_mode_screensaver.h"
 
 #include "base/bind.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "chrome/browser/chromeos/dbus/dbus_thread_manager.h"
@@ skipping 16 matching lines @@
 }
 
 KioskModeScreensaver::~KioskModeScreensaver() {
   chromeos::PowerManagerClient* power_manager =
       chromeos::DBusThreadManager::Get()->GetPowerManagerClient();
   if (power_manager->HasObserver(this))
     power_manager->RemoveObserver(this);
 }
 
 void KioskModeScreensaver::Setup() {
-
   // We should NOT be created if already logged in.
   CHECK(!chromeos::UserManager::Get()->user_is_logged_in());
 
   registrar_.Add(this, chrome::NOTIFICATION_LOGIN_USER_CHANGED,
                  content::NotificationService::AllSources());
 
   // We will register ourselves now and unregister if a user logs in.
   chromeos::PowerManagerClient* power_manager =
       chromeos::DBusThreadManager::Get()->GetPowerManagerClient();
   if (!power_manager->HasObserver(this))
@@ skipping 41 matching lines @@
 void InitializeKioskModeScreensaver() {
   if (g_kiosk_mode_screensaver) {
     LOG(WARNING) << "Screensaver was already initialized";
     return;
   }
 
   g_kiosk_mode_screensaver = new KioskModeScreensaver();
 }
 
 void ShutdownKioskModeScreensaver() {
-  if (!g_kiosk_mode_screensaver) {
-    LOG(WARNING) << "Screensaver shutdown called when uninitialized.";
-    return;
-  }
-
   delete g_kiosk_mode_screensaver;
   g_kiosk_mode_screensaver = NULL;
 }
 
 }  // namespace chromeos