Use constexpr TaskTraits constructor in chrome.

chrome/browser/chromeos/drive/write_on_cache_file.cc

Index: chrome/browser/chromeos/drive/write_on_cache_file.cc
diff --git a/chrome/browser/chromeos/drive/write_on_cache_file.cc b/chrome/browser/chromeos/drive/write_on_cache_file.cc
index c7676999439db81bff7e92102285eb6bd683e53a..04308017b5f8f15d90e2698727291aa261a6c455 100644
--- a/chrome/browser/chromeos/drive/write_on_cache_file.cc
+++ b/chrome/browser/chromeos/drive/write_on_cache_file.cc
@@ -40,8 +40,7 @@ void WriteOnCacheFileAfterOpenFile(
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   base::PostTaskWithTraitsAndReply(
-      FROM_HERE, base::TaskTraits().MayBlock().WithPriority(
-                     base::TaskPriority::USER_BLOCKING),
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::USER_BLOCKING},
       base::Bind(file_io_task_callback, error, local_cache_path),
       base::Bind(&RunCloseCallbackAndReplyTask, close_callback, reply, error));
 }