Convert Pass()→std::move() for iOS build.

ios/chrome/browser/history/history_service_factory.cc

 // 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/history/history_service_factory.h"
 
+#include <utility>
+
 #include "base/memory/singleton.h"
 #include "base/prefs/pref_service.h"
 #include "components/history/core/browser/history_database_params.h"
 #include "components/history/core/browser/history_service.h"
 #include "components/history/core/browser/visit_delegate.h"
 #include "components/history/ios/browser/history_database_helper.h"
 #include "components/keyed_service/core/service_access_type.h"
 #include "components/keyed_service/ios/browser_state_dependency_manager.h"
 #include "ios/chrome/browser/bookmarks/bookmark_model_factory.h"
 #include "ios/chrome/browser/browser_state/browser_state_otr_helper.h"
@@ skipping 56 matching lines @@
       new history::HistoryService(
           make_scoped_ptr(new HistoryClientImpl(
               ios::BookmarkModelFactory::GetForBrowserState(browser_state))),
           nullptr));
   if (!history_service->Init(
           browser_state->GetPrefs()->GetString(prefs::kAcceptLanguages),
           history::HistoryDatabaseParamsForPath(
               browser_state->GetStatePath()))) {
     return nullptr;
   }
-  return history_service.Pass();
+  return std::move(history_service);
 }
 
 web::BrowserState* HistoryServiceFactory::GetBrowserStateToUse(
     web::BrowserState* context) const {
   return GetBrowserStateRedirectedInIncognito(context);
 }
 
 bool HistoryServiceFactory::ServiceIsNULLWhileTesting() const {
   return true;
 }
 
 }  // namespace ios