Use constexpr TaskTraits constructor in chrome.

chrome/browser/chromeos/system_logs/debug_log_writer.cc

 // Copyright 2014 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/system_logs/debug_log_writer.h"
 
 #include <stdint.h>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 178 matching lines @@
 
     return;
   }
 
   base::FilePath compressed_output_path =
       tar_file_path.AddExtension(FILE_PATH_LITERAL(".gz"));
   base::FilePath user_log_dir =
       logging::GetSessionLogDir(*base::CommandLine::ForCurrentProcess());
 
   base::PostTaskWithTraits(
-      FROM_HERE,
-      base::TaskTraits().MayBlock().WithPriority(
-          base::TaskPriority::BACKGROUND),
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
       base::Bind(&AddUserLogsToArchive, user_log_dir, tar_file_path,
                  compressed_output_path, callback));
 }
 
 void InitializeLogFile(base::File* file,
                        const base::FilePath& file_path,
                        uint32_t flags) {
   base::FilePath dir = file_path.DirName();
   if (!base::DirectoryExists(dir)) {
     if (!base::CreateDirectory(dir)) {
@@ skipping 55 matching lines @@
       fileshelf.Append(FILE_PATH_LITERAL("combined-logs.tar"));
 
   // Get system logs from /var/log first, then add user-specific stuff.
   StartLogRetrieval(file_path,
                     false,
                     sequence_token_name,
                     base::Bind(&OnSystemLogsAdded, callback));
 }
 
 }  // namespace chromeos