Use constexpr TaskTraits constructor in chrome.

chrome/browser/chromeos/drive/fileapi/fileapi_worker.cc

Index: chrome/browser/chromeos/drive/fileapi/fileapi_worker.cc
diff --git a/chrome/browser/chromeos/drive/fileapi/fileapi_worker.cc b/chrome/browser/chromeos/drive/fileapi/fileapi_worker.cc
index fb745cd816eca7a6edd7ed443e710df22fdf8924..684d8415f724d8bc86e7ec64c5ec07c54a92bfed 100644
--- a/chrome/browser/chromeos/drive/fileapi/fileapi_worker.cc
+++ b/chrome/browser/chromeos/drive/fileapi/fileapi_worker.cc
@@ -185,7 +185,7 @@ void OpenFileAfterFileSystemOpenFile(int file_flags,
 
   // Cache file prepared for modification is available. Open it locally.
   base::PostTaskWithTraitsAndReplyWithResult(
-      FROM_HERE, base::TaskTraits().MayBlock(),
+      FROM_HERE, {base::MayBlock()},
       base::Bind(&OpenFile, local_path, file_flags),
       base::Bind(&RunOpenFileCallback, callback, close_callback));
 }