Use constexpr TaskTraits constructor in chrome.

chrome/browser/chrome_browser_main_linux.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/chrome_browser_main_linux.h"
 
 #include <fontconfig/fontconfig.h>
 
 #include <string>
 
@@ skipping 32 matching lines @@
 
   ChromeBrowserMainPartsPosix::ToolkitInitialized();
 }
 
 void ChromeBrowserMainPartsLinux::PreProfileInit() {
 #if !defined(OS_CHROMEOS)
   // Needs to be called after we have chrome::DIR_USER_DATA and
   // g_browser_process.  This happens in PreCreateThreads.
   // base::GetLinuxDistro() will initialize its value if needed.
   base::PostTaskWithTraits(
-      FROM_HERE,
-      base::TaskTraits().MayBlock().WithPriority(
-          base::TaskPriority::BACKGROUND),
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
       base::BindOnce(base::IgnoreResult(&base::GetLinuxDistro)));
 #endif
 
   media::AudioManager::SetGlobalAppName(
       l10n_util::GetStringUTF8(IDS_SHORT_PRODUCT_NAME));
 
 #if !defined(OS_CHROMEOS)
   // Forward to os_crypt the flag to use a specific password store.
   OSCrypt::SetStore(
       parsed_command_line().GetSwitchValueASCII(switches::kPasswordStore));
@@ skipping 27 matching lines @@
 }
 
 void ChromeBrowserMainPartsLinux::PostDestroyThreads() {
 #if !defined(OS_CHROMEOS)
   bluez::BluezDBusManager::Shutdown();
   bluez::DBusThreadManagerLinux::Shutdown();
 #endif
 
   ChromeBrowserMainPartsPosix::PostDestroyThreads();
 }