Use constexpr TaskTraits constructor in chrome.

chrome/browser/chromeos/settings/session_manager_operation.cc

Index: chrome/browser/chromeos/settings/session_manager_operation.cc
diff --git a/chrome/browser/chromeos/settings/session_manager_operation.cc b/chrome/browser/chromeos/settings/session_manager_operation.cc
index 6773ca38181fec55cf8f43c1e7d571a65f2b1482..efbcdd8e491b1e715abbc6cc7841364d4a952f59 100644
--- a/chrome/browser/chromeos/settings/session_manager_operation.cc
+++ b/chrome/browser/chromeos/settings/session_manager_operation.cc
@@ -90,11 +90,8 @@ void SessionManagerOperation::EnsurePublicKey(const base::Closure& callback) {
   if (force_key_load_ || !public_key_ || !public_key_->is_loaded()) {
     scoped_refptr<base::TaskRunner> task_runner =
         base::CreateTaskRunnerWithTraits(
-            base::TaskTraits()
-                .MayBlock()
-                .WithPriority(base::TaskPriority::BACKGROUND)
-                .WithShutdownBehavior(
-                    base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN));
+            {base::MayBlock(), base::TaskPriority::BACKGROUND,
+             base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN});
     base::PostTaskAndReplyWithResult(
         task_runner.get(), FROM_HERE,
         base::Bind(&SessionManagerOperation::LoadPublicKey, owner_key_util_,