Login Screen for Mus

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 <stddef.h>
 
 #include "base/location.h"
 #include "base/logging.h"
@@ skipping 106 matching lines @@
     : handler_(nullptr),
       login_display_delegate_(nullptr),
       view_(nullptr),
       display_type_(display_type),
       weak_factory_(this) {
 }
 
 UserSelectionScreen::~UserSelectionScreen() {
   proximity_auth::ScreenlockBridge::Get()->SetLockHandler(nullptr);
   ui::UserActivityDetector* activity_detector = ui::UserActivityDetector::Get();
-  if (activity_detector->HasObserver(this))
+  if (activity_detector && activity_detector->HasObserver(this))
     activity_detector->RemoveObserver(this);
 }
 
 void UserSelectionScreen::InitEasyUnlock() {
   proximity_auth::ScreenlockBridge::Get()->SetLockHandler(this);
 }
 
 void UserSelectionScreen::SetLoginDisplayDelegate(
     LoginDisplay::Delegate* login_display_delegate) {
   login_display_delegate_ = login_display_delegate;
@@ skipping 117 matching lines @@
 void UserSelectionScreen::SetView(UserBoardView* view) {
   view_ = view;
 }
 
 void UserSelectionScreen::Init(const user_manager::UserList& users,
                                bool show_guest) {
   users_ = users;
   show_guest_ = show_guest;
 
   ui::UserActivityDetector* activity_detector = ui::UserActivityDetector::Get();
-  if (!activity_detector->HasObserver(this))
+  if (activity_detector && !activity_detector->HasObserver(this))
     activity_detector->AddObserver(this);
 }
 
 void UserSelectionScreen::OnBeforeUserRemoved(const AccountId& account_id) {
   for (user_manager::UserList::iterator it = users_.begin(); it != users_.end();
        ++it) {
     if ((*it)->GetAccountId() == account_id) {
       users_.erase(it);
       break;
     }
@@ skipping 277 matching lines @@
   // The user profile should exist if and only if this is the lock screen.
   DCHECK_EQ(!!profile, GetScreenType() == LOCK_SCREEN);
 
   if (!profile)
     profile = profile_helper->GetSigninProfile();
 
   return EasyUnlockService::Get(profile);
 }
 
 }  // namespace chromeos