Use constexpr TaskTraits constructor in chrome.

chrome/browser/search/local_files_ntp_source.cc

Index: chrome/browser/search/local_files_ntp_source.cc
diff --git a/chrome/browser/search/local_files_ntp_source.cc b/chrome/browser/search/local_files_ntp_source.cc
index 821f2d6d4d412a6df2583251e6dbfedd6864e003..8b7391a7c0353ac638e71509dcfe7c39853ee64f 100644
--- a/chrome/browser/search/local_files_ntp_source.cc
+++ b/chrome/browser/search/local_files_ntp_source.cc
@@ -116,8 +116,7 @@ void SendLocalFileResourceWithOrigin(
   content::URLDataSource::GotDataCallback wrapper =
       base::Bind(&CheckLocalIncludes, callback);
   base::PostTaskWithTraitsAndReplyWithResult(
-      FROM_HERE, base::TaskTraits().MayBlock().WithPriority(
-                     base::TaskPriority::BACKGROUND),
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
       base::Bind(&ReadFileAndReturn, fullpath),
       base::Bind(&CallbackWithLoadedResource, origin, wrapper));
 }