[ObjC ARC] Converts ios/chrome/browser/signin:signin to ARC.

ios/chrome/browser/signin/account_consistency_service_factory.mm

 // Copyright 2015 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 "ios/chrome/browser/signin/account_consistency_service_factory.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/memory/singleton.h"
 #include "components/keyed_service/ios/browser_state_dependency_manager.h"
 #include "components/signin/ios/browser/account_consistency_service.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #include "ios/chrome/browser/content_settings/cookie_settings_factory.h"
 #include "ios/chrome/browser/signin/account_reconcilor_factory.h"
 #include "ios/chrome/browser/signin/gaia_cookie_manager_service_factory.h"
 #include "ios/chrome/browser/signin/signin_client_factory.h"
 #include "ios/chrome/browser/signin/signin_manager_factory.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace ios {
 
 AccountConsistencyServiceFactory::AccountConsistencyServiceFactory()
     : BrowserStateKeyedServiceFactory(
           "AccountConsistencyService",
           BrowserStateDependencyManager::GetInstance()) {
   DependsOn(ios::AccountReconcilorFactory::GetInstance());
   DependsOn(ios::CookieSettingsFactory::GetInstance());
   DependsOn(GaiaCookieManagerServiceFactory::GetInstance());
   DependsOn(SigninClientFactory::GetInstance());
@@ skipping 28 matching lines @@
   return base::MakeUnique<AccountConsistencyService>(
       chrome_browser_state,
       ios::AccountReconcilorFactory::GetForBrowserState(chrome_browser_state),
       ios::CookieSettingsFactory::GetForBrowserState(chrome_browser_state),
       GaiaCookieManagerServiceFactory::GetForBrowserState(chrome_browser_state),
       SigninClientFactory::GetForBrowserState(chrome_browser_state),
       ios::SigninManagerFactory::GetForBrowserState(chrome_browser_state));
 }
 
 }  // namespace ios