Clean up LoginUIService. Remove Singleton behavior from PeopleHandler

chrome/browser/ui/webui/signin/login_ui_service.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/ui/webui/signin/login_ui_service.h"
 
 #include "build/build_config.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/signin/signin_promo.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/chrome_pages.h"
 #include "chrome/browser/ui/scoped_tabbed_browser_displayer.h"
 #include "chrome/browser/ui/webui/signin/login_ui_service_factory.h"
 #include "chrome/common/url_constants.h"
 #include "components/signin/core/browser/signin_header_helper.h"
 #include "components/signin/core/common/profile_management_switches.h"
 
 LoginUIService::LoginUIService(Profile* profile)
-    : ui_(NULL), profile_(profile) {
+    : profile_(profile) {
 }
 
 LoginUIService::~LoginUIService() {}
 
 void LoginUIService::AddObserver(LoginUIService::Observer* observer) {
   observer_list_.AddObserver(observer);
 }
 
 void LoginUIService::RemoveObserver(LoginUIService::Observer* observer) {
   observer_list_.RemoveObserver(observer);
 }
 
+LoginUIService::LoginUI* LoginUIService::current_login_ui() const {
+  return ui_list_.empty() ? nullptr : ui_list_.front();
+}
+
 void LoginUIService::SetLoginUI(LoginUI* ui) {
-  DCHECK(!current_login_ui() || current_login_ui() == ui);
-  ui_ = ui;
-  FOR_EACH_OBSERVER(Observer, observer_list_, OnLoginUIShown(ui_));
+  ui_list_.remove(ui);
+  ui_list_.push_front(ui);
 }
 
 void LoginUIService::LoginUIClosed(LoginUI* ui) {
-  if (current_login_ui() != ui)
-    return;
-
-  ui_ = NULL;
-  FOR_EACH_OBSERVER(Observer, observer_list_, OnLoginUIClosed(ui));
+  ui_list_.remove(ui);
 }
 
 void LoginUIService::SyncConfirmationUIClosed(
     SyncConfirmationUIClosedResult result) {
   FOR_EACH_OBSERVER(
       Observer,
       observer_list_,
       OnSyncConfirmationUIClosed(result));
 }
 
-void LoginUIService::UntrustedLoginUIShown() {
-  FOR_EACH_OBSERVER(Observer, observer_list_, OnUntrustedLoginUIShown());
-}
-
 void LoginUIService::ShowLoginPopup() {
 #if defined(OS_CHROMEOS)
   NOTREACHED();
 #else
   chrome::ScopedTabbedBrowserDisplayer displayer(profile_);
   chrome::ShowBrowserSignin(
       displayer.browser(),
       signin_metrics::AccessPoint::ACCESS_POINT_EXTENSIONS);
 #endif
 }
 
 void LoginUIService::DisplayLoginResult(Browser* browser,
                                         const base::string16& message) {
 #if defined(OS_CHROMEOS)
   // ChromeOS doesn't have the avatar bubble so it never calls this function.
   NOTREACHED();
 #endif
   last_login_result_ = message;
   browser->window()->ShowAvatarBubbleFromAvatarButton(
       message.empty() ? BrowserWindow::AVATAR_BUBBLE_MODE_CONFIRM_SIGNIN
                       : BrowserWindow::AVATAR_BUBBLE_MODE_SHOW_ERROR,
       signin::ManageAccountsParams(),
       signin_metrics::AccessPoint::ACCESS_POINT_EXTENSIONS);
 }
 
 const base::string16& LoginUIService::GetLastLoginResult() {
   return last_login_result_;
 }