Use constexpr TaskTraits constructor in chromeos.

chromeos/network/client_cert_resolver.cc

Index: chromeos/network/client_cert_resolver.cc
diff --git a/chromeos/network/client_cert_resolver.cc b/chromeos/network/client_cert_resolver.cc
index 74cb13651b79d685c32cc38f4e9ed287aa0dc216..4f174b51e196abdf5139af1641f3a614b1678eb3 100644
--- a/chromeos/network/client_cert_resolver.cc
+++ b/chromeos/network/client_cert_resolver.cc
@@ -516,10 +516,7 @@ void ClientCertResolver::ResolveNetworks(
   resolve_task_running_ = true;
   base::PostTaskWithTraitsAndReplyWithResult(
       FROM_HERE,
-      base::TaskTraits()
-          .WithShutdownBehavior(
-              base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN)
-          .MayBlock(),
+      {base::MayBlock(), base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN},
       base::Bind(&FindCertificateMatches, CertLoader::Get()->all_certs(),
                  CertLoader::Get()->system_certs(),
                  base::Owned(networks_to_resolve.release()), Now()),