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

ios/chrome/browser/suggestions/suggestions_service_factory.mm

 // 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 "ios/chrome/browser/suggestions/suggestions_service_factory.h"
 
 #include <utility>
 
 #include "base/files/file_path.h"
 #include "base/memory/ptr_util.h"
@@ skipping 11 matching lines @@
 #include "components/suggestions/suggestions_service_impl.h"
 #include "components/suggestions/suggestions_store.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #include "ios/chrome/browser/signin/oauth2_token_service_factory.h"
 #include "ios/chrome/browser/signin/signin_manager_factory.h"
 #include "ios/chrome/browser/suggestions/image_fetcher_impl.h"
 #include "ios/chrome/browser/sync/ios_chrome_profile_sync_service_factory.h"
 #include "ios/web/public/browser_state.h"
 #include "ios/web/public/web_thread.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace suggestions {
 namespace {
 const base::FilePath::CharType kThumbnailDirectory[] =
     FILE_PATH_LITERAL("Thumbnail");
 }
 
 // static
 SuggestionsServiceFactory* SuggestionsServiceFactory::GetInstance() {
   return base::Singleton<SuggestionsServiceFactory>::get();
 }
@@ skipping 53 matching lines @@
       browser_state->GetRequestContext(), std::move(suggestions_store),
       std::move(thumbnail_manager), std::move(blacklist_store));
 }
 
 void SuggestionsServiceFactory::RegisterBrowserStatePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   SuggestionsServiceImpl::RegisterProfilePrefs(registry);
 }
 
 }  // namespace suggestions