Make UserActivityDetector a singleton

chrome/browser/chromeos/login/screens/user_selection_screen.cc

 // Copyright 2014 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/login/screens/user_selection_screen.h"
 
-#include "ash/shell.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/prefs/pref_service.h"
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_process_platform_part.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host_impl.h"
 #include "chrome/browser/chromeos/login/users/chrome_user_manager.h"
 #include "chrome/browser/chromeos/login/users/multi_profile_user_controller.h"
 #include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
@@ skipping 81 matching lines @@
   user_dict->Set(kKeyInitialKeyboardLayout,
                  GetCurrentKeyboardLayout().release());
 }
 
 }  // namespace
 
 UserSelectionScreen::UserSelectionScreen() : handler_(NULL) {
 }
 
 UserSelectionScreen::~UserSelectionScreen() {
-#if !defined(USE_ATHENA)
-  // TODO(dpolukhin): crbug.com/408752
   wm::UserActivityDetector* activity_detector =
-      ash::Shell::GetInstance()->user_activity_detector();
+      wm::UserActivityDetector::Get();
   if (activity_detector->HasObserver(this))
     activity_detector->RemoveObserver(this);
-#endif
 }
 
 // static
 void UserSelectionScreen::FillUserDictionary(
     user_manager::User* user,
     bool is_owner,
     bool is_signin_to_add,
     ScreenlockBridge::LockHandler::AuthType auth_type,
     const std::vector<std::string>* public_session_recommended_locales,
     base::DictionaryValue* user_dict) {
@@ skipping 77 matching lines @@
 
 void UserSelectionScreen::SetHandler(LoginDisplayWebUIHandler* handler) {
   handler_ = handler;
 }
 
 void UserSelectionScreen::Init(const user_manager::UserList& users,
                                bool show_guest) {
   users_ = users;
   show_guest_ = show_guest;
 
-#if !defined(USE_ATHENA)
-  // TODO(dpolukhin): crbug.com/408752
   wm::UserActivityDetector* activity_detector =
-      ash::Shell::GetInstance()->user_activity_detector();
+      wm::UserActivityDetector::Get();
   if (!activity_detector->HasObserver(this))
     activity_detector->AddObserver(this);
-#endif
 }
 
 void UserSelectionScreen::OnBeforeUserRemoved(const std::string& username) {
   for (user_manager::UserList::iterator it = users_.begin(); it != users_.end();
        ++it) {
     if ((*it)->email() == username) {
       users_.erase(it);
       break;
     }
   }
@@ skipping 146 matching lines @@
 }
 
 ScreenlockBridge::LockHandler::AuthType UserSelectionScreen::GetAuthType(
     const std::string& username) const {
   if (user_auth_type_map_.find(username) == user_auth_type_map_.end())
     return ScreenlockBridge::LockHandler::OFFLINE_PASSWORD;
   return user_auth_type_map_.find(username)->second;
 }
 
 }  // namespace chromeos