Use constexpr TaskTraits constructor in extensions.

extensions/browser/api/file_handlers/directory_util.cc

Index: extensions/browser/api/file_handlers/directory_util.cc
diff --git a/extensions/browser/api/file_handlers/directory_util.cc b/extensions/browser/api/file_handlers/directory_util.cc
index 96d8faa38d2a734d6e86260f26ac0d0c00cf6175..7e6a0718dc5f849bf209a64bf564526ce7b3fd0b 100644
--- a/extensions/browser/api/file_handlers/directory_util.cc
+++ b/extensions/browser/api/file_handlers/directory_util.cc
@@ -43,7 +43,7 @@ void EntryIsDirectory(content::BrowserContext* context,
 #endif
 
   base::PostTaskWithTraitsAndReplyWithResult(
-      FROM_HERE, base::TaskTraits().MayBlock(),
+      FROM_HERE, {base::MayBlock()},
       base::Bind(&GetIsDirectoryFromFileInfo, path), callback);
 }