Login Screen for Mus

chrome/browser/chromeos/login/ui/webui_login_display.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/ui/webui_login_display.h"
 
 #include "chrome/browser/chromeos/accessibility/accessibility_manager.h"
 #include "chrome/browser/chromeos/login/lock/screen_locker.h"
 #include "chrome/browser/chromeos/login/screens/chrome_user_selection_screen.h"
 #include "chrome/browser/chromeos/login/signin_screen_controller.h"
@@ skipping 17 matching lines @@
 #include "ui/views/widget/widget.h"
 
 namespace chromeos {
 
 // WebUILoginDisplay, public: --------------------------------------------------
 
 WebUILoginDisplay::~WebUILoginDisplay() {
   if (webui_handler_)
     webui_handler_->ResetSigninScreenHandlerDelegate();
   ui::UserActivityDetector* activity_detector = ui::UserActivityDetector::Get();
-  if (activity_detector->HasObserver(this))
+  if (activity_detector && activity_detector->HasObserver(this))
     activity_detector->RemoveObserver(this);
 }
 
 // LoginDisplay implementation: ------------------------------------------------
 
 WebUILoginDisplay::WebUILoginDisplay(LoginDisplay::Delegate* delegate)
     : LoginDisplay(delegate, gfx::Rect()) {}
 
 void WebUILoginDisplay::ClearAndEnablePassword() {
   if (webui_handler_)
       webui_handler_->ClearAndEnablePassword();
 }
 
 void WebUILoginDisplay::Init(const user_manager::UserList& users,
                              bool show_guest,
                              bool show_users,
                              bool show_new_user) {
   // Testing that the delegate has been set.
   DCHECK(delegate_);
   SignInScreenController::Get()->Init(users, show_guest);
   show_guest_ = show_guest;
   show_users_ = show_users;
   show_new_user_ = show_new_user;
 
   ui::UserActivityDetector* activity_detector = ui::UserActivityDetector::Get();
-  if (!activity_detector->HasObserver(this))
+  if (activity_detector && !activity_detector->HasObserver(this))
     activity_detector->AddObserver(this);
 }
 
 // ---- Common methods
 
 // ---- User selection screen methods
 
 void WebUILoginDisplay::HandleGetUsers() {
   SignInScreenController::Get()->SendUserList();
 }
@@ skipping 250 matching lines @@
 }
 
 bool WebUILoginDisplay::IsUserWhitelisted(const AccountId& account_id) {
   DCHECK(delegate_);
   if (delegate_)
     return delegate_->IsUserWhitelisted(account_id);
   return true;
 }
 
 }  // namespace chromeos