Use constexpr TaskTraits constructor in chrome.

chrome/browser/chromeos/system_logs/command_line_log_source.cc

Index: chrome/browser/chromeos/system_logs/command_line_log_source.cc
diff --git a/chrome/browser/chromeos/system_logs/command_line_log_source.cc b/chrome/browser/chromeos/system_logs/command_line_log_source.cc
index 621f37310477f58720b02a300e90fb7dd984ec4e..d97f63993fc2aca2b1c2f6e4d8b20558dcb0133a 100644
--- a/chrome/browser/chromeos/system_logs/command_line_log_source.cc
+++ b/chrome/browser/chromeos/system_logs/command_line_log_source.cc
@@ -114,11 +114,10 @@ void CommandLineLogSource::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(&ExecuteCommandLines, response),
-                                   base::Bind(callback, base::Owned(response)));
+  base::PostTaskWithTraitsAndReply(
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
+      base::Bind(&ExecuteCommandLines, response),
+      base::Bind(callback, base::Owned(response)));
 }
 
 }  // namespace system_logs