Make UserActivityDetector a singleton

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 "ash/screensaver/screensaver_view.h"
-#include "ash/shell.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/chromeos/kiosk_mode/kiosk_mode_settings.h"
 #include "chrome/browser/chromeos/login/existing_user_controller.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host_impl.h"
 #include "chrome/browser/chromeos/policy/app_pack_updater.h"
@@ skipping 173 matching lines @@
     // Delete it.
     content::BrowserThread::PostTask(
         content::BrowserThread::FILE,
         FROM_HERE,
         base::Bind(
             &extensions::file_util::DeleteFile, extension_base_path_, true));
   }
 
   // In case we're shutting down without ever triggering the active
   // notification and/or logging in.
-  if (ash::Shell::GetInstance() &&
-      ash::Shell::GetInstance()->user_activity_detector() &&
-      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 KioskModeScreensaver::GetScreensaverCrxPath() {
   chromeos::KioskModeSettings::Get()->GetScreensaverPath(
       base::Bind(&KioskModeScreensaver::ScreensaverPathCallback,
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
 void KioskModeScreensaver::ScreensaverPathCallback(
     const base::FilePath& screensaver_crx) {
@@ skipping 29 matching lines @@
 void KioskModeScreensaver::SetupScreensaver(
     scoped_refptr<Extension> extension,
     const base::FilePath& extension_base_path) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   extension_base_path_ = extension_base_path;
 
   // If the user is already logged in, don't need to display the screensaver.
   if (chromeos::LoginState::Get()->IsUserLoggedIn())
     return;
 
-  ash::Shell::GetInstance()->user_activity_detector()->AddObserver(this);
+  wm::UserActivityDetector::Get()->AddObserver(this);
 
   ExtensionService* extension_service = GetDefaultExtensionService();
   // Add the extension to the extension service and display the screensaver.
   if (extension_service) {
     extension_service->AddExtension(extension.get());
     ash::ShowScreensaver(
         extensions::AppLaunchInfo::GetFullLaunchURL(extension.get()));
   } else {
     LOG(ERROR) << "Couldn't get extension system. Unable to load screensaver!";
     ShutdownKioskModeScreensaver();
   }
 }
 
 void KioskModeScreensaver::OnUserActivity(const ui::Event* event) {
   // We don't want to handle further user notifications; we'll either login
   // the user and close out or or at least close the screensaver.
-  ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
+  wm::UserActivityDetector::Get()->RemoveObserver(this);
 
   // Find the retail mode login page.
   if (LoginDisplayHostImpl::default_host()) {
     LoginDisplayHostImpl* webui_host =
         static_cast<LoginDisplayHostImpl*>(
             LoginDisplayHostImpl::default_host());
     OobeUI* oobe_ui = webui_host->GetOobeUI();
 
     // Show the login spinner.
     if (oobe_ui)
@@ skipping 26 matching lines @@
 
   g_kiosk_mode_screensaver = new KioskModeScreensaver();
 }
 
 void ShutdownKioskModeScreensaver() {
   delete g_kiosk_mode_screensaver;
   g_kiosk_mode_screensaver = NULL;
 }
 
 }  // namespace chromeos