Use constexpr TaskTraits constructor in chrome.

chrome/browser/ui/app_list/arc/arc_app_list_prefs.cc

 // Copyright 2015 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/app_list/arc/arc_app_list_prefs.h"
 
 #include <stddef.h>
 
 #include <string>
 
@@ skipping 888 matching lines @@
   const bool removed = apps->Remove(app_id, nullptr);
   DCHECK(removed);
 
   DCHECK(tracked_apps_.count(app_id));
   for (auto& observer : observer_list_)
     observer.OnAppRemoved(app_id);
   tracked_apps_.erase(app_id);
 
   // Remove local data on file system.
   base::PostTaskWithTraits(
-      FROM_HERE, base::TaskTraits().MayBlock().WithPriority(
-                     base::TaskPriority::BACKGROUND),
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
       base::Bind(&DeleteAppFolderFromFileThread, app_path));
 }
 
 void ArcAppListPrefs::AddOrUpdatePackagePrefs(
     PrefService* prefs, const arc::mojom::ArcPackageInfo& package) {
   DCHECK(IsArcAndroidEnabledForProfile(profile_));
   const std::string& package_name = package.package_name;
   default_apps_.MaybeMarkPackageUninstalled(package_name, false);
   if (package_name.empty()) {
     VLOG(2) << "Package name cannot be empty.";
@@ skipping 418 matching lines @@
   if (!base::StringToInt64(install_time_str, &install_time_i64))
     return base::Time();
   return base::Time::FromInternalValue(install_time_i64);
 }
 
 void ArcAppListPrefs::InstallIcon(const std::string& app_id,
                                   ui::ScaleFactor scale_factor,
                                   const std::vector<uint8_t>& content_png) {
   base::FilePath icon_path = GetIconPath(app_id, scale_factor);
   base::PostTaskWithTraitsAndReplyWithResult(
-      FROM_HERE, base::TaskTraits().MayBlock().WithPriority(
-                     base::TaskPriority::BACKGROUND),
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
       base::Bind(&InstallIconFromFileThread, app_id, scale_factor, icon_path,
                  content_png),
       base::Bind(&ArcAppListPrefs::OnIconInstalled,
                  weak_ptr_factory_.GetWeakPtr(), app_id, scale_factor));
 }
 
 void ArcAppListPrefs::OnIconInstalled(const std::string& app_id,
                                       ui::ScaleFactor scale_factor,
                                       bool install_succeed) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
@@ skipping 75 matching lines @@
                                           int64_t last_backup_android_id,
                                           int64_t last_backup_time,
                                           bool should_sync,
                                           bool system)
     : package_name(package_name),
       package_version(package_version),
       last_backup_android_id(last_backup_android_id),
       last_backup_time(last_backup_time),
       should_sync(should_sync),
       system(system) {}