Use constexpr TaskTraits constructor in chrome.

chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.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/ui/webui/chromeos/login/gaia_screen_handler.h"
 
 #include "ash/system/devicetype_utils.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/guid.h"
@@ skipping 251 matching lines @@
     LoadAuthExtension(true /* force */, false /* offline */);
   }
 }
 
 void GaiaScreenHandler::DisableRestrictiveProxyCheckForTest() {
   disable_restrictive_proxy_check_for_test_ = true;
 }
 
 void GaiaScreenHandler::LoadGaia(const GaiaContext& context) {
   base::PostTaskWithTraitsAndReplyWithResult(
-      FROM_HERE, base::TaskTraits().MayBlock().WithPriority(
-                     base::TaskPriority::BACKGROUND),
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
       base::Bind(&version_loader::GetVersion, version_loader::VERSION_SHORT),
       base::Bind(&GaiaScreenHandler::LoadGaiaWithVersion,
                  weak_factory_.GetWeakPtr(), context));
 }
 
 void GaiaScreenHandler::LoadGaiaWithVersion(
     const GaiaContext& context,
     const std::string& platform_version) {
   base::DictionaryValue params;
 
@@ skipping 691 matching lines @@
 SigninScreenHandlerDelegate* GaiaScreenHandler::Delegate() {
   return signin_screen_handler_->delegate_;
 }
 
 bool GaiaScreenHandler::IsRestrictiveProxy() const {
   return !disable_restrictive_proxy_check_for_test_ &&
          !IsOnline(captive_portal_status_);
 }
 
 }  // namespace chromeos