Use constexpr TaskTraits constructor in chrome.

chrome/browser/ui/webui/extensions/extension_loader_handler.cc

Index: chrome/browser/ui/webui/extensions/extension_loader_handler.cc
diff --git a/chrome/browser/ui/webui/extensions/extension_loader_handler.cc b/chrome/browser/ui/webui/extensions/extension_loader_handler.cc
index 846123f953910177c741faf0ed8c5e77cb1be6fd..8bafdd5a1af4db9cbce3f16633a363d5d382b3df 100644
--- a/chrome/browser/ui/webui/extensions/extension_loader_handler.cc
+++ b/chrome/browser/ui/webui/extensions/extension_loader_handler.cc
@@ -124,9 +124,7 @@ void ExtensionLoaderHandler::GetManifestError(
   // This will read the manifest and call AddFailure with the read manifest
   // contents.
   base::PostTaskWithTraitsAndReplyWithResult(
-      FROM_HERE,
-      base::TaskTraits().MayBlock().WithPriority(
-          base::TaskPriority::USER_BLOCKING),
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::USER_BLOCKING},
       base::Bind(&ReadFileToString, extension_path.Append(kManifestFilename)),
       base::Bind(callback, extension_path, error, line));
 }