Use constexpr TaskTraits constructor in chrome.

chrome/browser/dom_distiller/dom_distiller_service_factory.cc

Index: chrome/browser/dom_distiller/dom_distiller_service_factory.cc
diff --git a/chrome/browser/dom_distiller/dom_distiller_service_factory.cc b/chrome/browser/dom_distiller/dom_distiller_service_factory.cc
index b6891faf1579b0570f3b25620cc23a13dd3a75fb..01e1510f863c083def3fb0a88e86bf483a5c656f 100644
--- a/chrome/browser/dom_distiller/dom_distiller_service_factory.cc
+++ b/chrome/browser/dom_distiller/dom_distiller_service_factory.cc
@@ -55,8 +55,7 @@ KeyedService* DomDistillerServiceFactory::BuildServiceInstanceFor(
     content::BrowserContext* profile) const {
   scoped_refptr<base::SequencedTaskRunner> background_task_runner =
       base::CreateSequencedTaskRunnerWithTraits(
-          base::TaskTraits().MayBlock().WithPriority(
-              base::TaskPriority::BACKGROUND));
+          {base::MayBlock(), base::TaskPriority::BACKGROUND});
 
   std::unique_ptr<leveldb_proto::ProtoDatabaseImpl<ArticleEntry>> db(
       new leveldb_proto::ProtoDatabaseImpl<ArticleEntry>(