Make UserActivityDetector a singleton

chrome/browser/chromeos/kiosk_mode/kiosk_mode_idle_logout.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_idle_logout.h"
 
 #include "ash/shell.h"
 #include "base/bind.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
@@ skipping 24 matching lines @@
 KioskModeIdleLogout::KioskModeIdleLogout() {
   if (KioskModeSettings::Get()->is_initialized()) {
     Setup();
   } else {
     KioskModeSettings::Get()->Initialize(base::Bind(&KioskModeIdleLogout::Setup,
                                                     base::Unretained(this)));
   }
 }
 
 KioskModeIdleLogout::~KioskModeIdleLogout() {
-  if (ash::Shell::HasInstance() &&
-      ash::Shell::GetInstance()->user_activity_detector()->HasObserver(this))
-    ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
+  wm::UserActivityDetector* user_activity_detector =
+      wm::UserActivityDetector::Get();
+  if (user_activity_detector && user_activity_detector->HasObserver(this))
+    user_activity_detector->RemoveObserver(this);
 }
 
 void KioskModeIdleLogout::Setup() {
   if (user_manager::UserManager::Get()->IsLoggedInAsDemoUser()) {
     // This means that we're recovering from a crash.  The user is already
     // logged in, so go ahead and start the timer.
     Start();
   } else {
     registrar_.Add(this, chrome::NOTIFICATION_LOGIN_USER_CHANGED,
                    content::NotificationService::AllSources());
   }
 }
 
 void KioskModeIdleLogout::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
   if (type == chrome::NOTIFICATION_LOGIN_USER_CHANGED) {
     Start();
     registrar_.RemoveAll();
   }
 }
 
 void KioskModeIdleLogout::OnUserActivity(const ui::Event* event) {
   IdleLogoutDialogView::CloseDialog();
   ResetTimer();
 }
 
 void KioskModeIdleLogout::Start() {
-  if (!ash::Shell::GetInstance()->user_activity_detector()->HasObserver(this))
-    ash::Shell::GetInstance()->user_activity_detector()->AddObserver(this);
+  if (!wm::UserActivityDetector::Get()->HasObserver(this))
+    wm::UserActivityDetector::Get()->AddObserver(this);
   ResetTimer();
 }
 
 void KioskModeIdleLogout::ResetTimer() {
   if (timer_.IsRunning()) {
     timer_.Reset();
   } else {
     // OneShotTimer destroys the posted task after running it, so Reset()
     // isn't safe to call on a timer that's already fired.
     timer_.Start(FROM_HERE, KioskModeSettings::Get()->GetIdleLogoutTimeout(),
                  base::Bind(&KioskModeIdleLogout::OnTimeout,
                             base::Unretained(this)));
   }
 }
 
 void KioskModeIdleLogout::OnTimeout() {
   IdleLogoutDialogView::ShowDialog();
 }
 
 }  // namespace chromeos