Use constexpr TaskTraits constructor in chrome.

chrome/browser/chromeos/hats/hats_notification_controller.cc

Index: chrome/browser/chromeos/hats/hats_notification_controller.cc
diff --git a/chrome/browser/chromeos/hats/hats_notification_controller.cc b/chrome/browser/chromeos/hats/hats_notification_controller.cc
index 9705ba2b824f808b5d0d6254e1503ca1e74de756..36ee547d36711c652c3d26db709fcbfc2702971f 100644
--- a/chrome/browser/chromeos/hats/hats_notification_controller.cc
+++ b/chrome/browser/chromeos/hats/hats_notification_controller.cc
@@ -114,8 +114,7 @@ HatsNotificationController::HatsNotificationController(
       image_fetcher_(image_fetcher),
       weak_pointer_factory_(this) {
   base::PostTaskWithTraitsAndReplyWithResult(
-      FROM_HERE, base::TaskTraits().MayBlock().WithPriority(
-                     base::TaskPriority::BACKGROUND),
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
       base::Bind(&IsNewDevice, kHatsNewDeviceThresholdDays),
       base::Bind(&HatsNotificationController::Initialize,
                  weak_pointer_factory_.GetWeakPtr()));