Use constexpr TaskTraits constructor in chrome.

chrome/browser/chromeos/system_logs/touch_log_source_x11.cc

Index: chrome/browser/chromeos/system_logs/touch_log_source_x11.cc
diff --git a/chrome/browser/chromeos/system_logs/touch_log_source_x11.cc b/chrome/browser/chromeos/system_logs/touch_log_source_x11.cc
index 1ff4135c03c21baa451b771df36205761c859b65..a7ee627cea30674111af758ad54464f1fb30e81b 100644
--- a/chrome/browser/chromeos/system_logs/touch_log_source_x11.cc
+++ b/chrome/browser/chromeos/system_logs/touch_log_source_x11.cc
@@ -62,11 +62,10 @@ void TouchLogSource::Fetch(const SysLogsSourceCallback& callback) {
   DCHECK(!callback.is_null());
 
   SystemLogsResponse* response = new SystemLogsResponse;
-  base::PostTaskWithTraitsAndReply(FROM_HERE,
-                                   base::TaskTraits().MayBlock().WithPriority(
-                                       base::TaskPriority::BACKGROUND),
-                                   base::Bind(&GetTouchLogsX11, response),
-                                   base::Bind(callback, base::Owned(response)));
+  base::PostTaskWithTraitsAndReply(
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
+      base::Bind(&GetTouchLogsX11, response),
+      base::Bind(callback, base::Owned(response)));
 }
 
 }  // namespace system_logs