Use constexpr TaskTraits constructor in chrome.

chrome/browser/chromeos/base/locale_util.cc

 // Copyright 2013 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/chromeos/base/locale_util.h"
 
 #include <utility>
 #include <vector>
 
 #include "base/task_scheduler/post_task.h"
@@ skipping 106 matching lines @@
                     const bool login_layouts_only,
                     const SwitchLanguageCallback& callback,
                     Profile* profile) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   std::unique_ptr<SwitchLanguageData> data(
       new SwitchLanguageData(locale, enable_locale_keyboard_layouts,
                              login_layouts_only, callback, profile));
   base::Closure reloader(
       base::Bind(&SwitchLanguageDoReloadLocale, base::Unretained(data.get())));
   base::PostTaskWithTraitsAndReply(
-      FROM_HERE, base::TaskTraits().MayBlock().WithPriority(
-                     base::TaskPriority::BACKGROUND),
-      reloader,
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND}, reloader,
       base::Bind(&FinishSwitchLanguage, base::Passed(std::move(data))));
 }
 
 }  // namespace locale_util
 }  // namespace chromeos