Use constexpr TaskTraits constructor in chrome.

chrome/browser/chromeos/policy/user_policy_manager_factory_chromeos.cc

 // Copyright (c) 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/policy/user_policy_manager_factory_chromeos.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 223 matching lines @@
 
   std::unique_ptr<UserCloudPolicyStoreChromeOS> store =
       base::MakeUnique<UserCloudPolicyStoreChromeOS>(
           chromeos::DBusThreadManager::Get()->GetCryptohomeClient(),
           chromeos::DBusThreadManager::Get()->GetSessionManagerClient(),
           background_task_runner, account_id, policy_key_dir,
           is_active_directory);
 
   scoped_refptr<base::SequencedTaskRunner> backend_task_runner =
       base::CreateSequencedTaskRunnerWithTraits(
-          base::TaskTraits()
-              .MayBlock()
-              .WithPriority(base::TaskPriority::BACKGROUND)
-              .WithShutdownBehavior(
-                  base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN));
+          {base::MayBlock(), base::TaskPriority::BACKGROUND,
+           base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN});
   scoped_refptr<base::SequencedTaskRunner> io_task_runner =
       content::BrowserThread::GetTaskRunnerForThread(
           content::BrowserThread::IO);
   std::unique_ptr<CloudExternalDataManager> external_data_manager(
       new UserCloudExternalDataManager(base::Bind(&GetChromePolicyDetails),
                                        backend_task_runner, io_task_runner,
                                        external_data_dir, store.get()));
   if (force_immediate_load)
     store->LoadImmediately();
 
@@ skipping 67 matching lines @@
 
 bool UserPolicyManagerFactoryChromeOS::HasTestingFactory(
     content::BrowserContext* context) {
   return false;
 }
 
 void UserPolicyManagerFactoryChromeOS::CreateServiceNow(
     content::BrowserContext* context) {}
 
 }  // namespace policy