Add chrome/browser/extensions to "GN check"

chrome/browser/extensions/api/file_system/file_system_api.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/extensions/api/file_system/file_system_api.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <set>
@@ skipping 57 matching lines @@
 
 #if defined(OS_CHROMEOS)
 #include "base/strings/string16.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chrome/browser/chromeos/app_mode/kiosk_app_manager.h"
 #include "chrome/browser/chromeos/file_manager/app_id.h"
 #include "chrome/browser/chromeos/file_manager/filesystem_api_util.h"
 #include "chrome/browser/extensions/api/file_system/request_file_system_dialog_view.h"
 #include "chrome/browser/extensions/api/file_system/request_file_system_notification.h"
 #include "chrome/browser/ui/simple_message_box.h"
-#include "components/prefs/testing_pref_service.h"
 #include "components/user_manager/user_manager.h"
 #include "extensions/browser/event_router.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/manifest_handlers/kiosk_mode_info.h"
 #include "url/url_constants.h"
 #endif
 
 using apps::SavedFileEntry;
 using apps::SavedFilesService;
@@ skipping 1359 matching lines @@
     return RespondNow(Error(kNotSupportedOnNonKioskSessionError));
   std::vector<api::file_system::Volume> result_volume_list;
   FillVolumeList(chrome_details_.GetProfile(), &result_volume_list);
 
   return RespondNow(ArgumentList(
       api::file_system::GetVolumeList::Results::Create(result_volume_list)));
 }
 #endif
 
 }  // namespace extensions