Use constexpr TaskTraits constructor in base.

base/trace_event/trace_log.cc

Index: base/trace_event/trace_log.cc
diff --git a/base/trace_event/trace_log.cc b/base/trace_event/trace_log.cc
index d1e0fc3839bec77c7ea07f97269fc9b79bf6eb8f..b6570fdade052b8e93e2bc266975b1d1f5a97498 100644
--- a/base/trace_event/trace_log.cc
+++ b/base/trace_event/trace_log.cc
@@ -971,11 +971,8 @@ void TraceLog::FinishFlush(int generation, bool discard_events) {
   if (use_worker_thread_) {
     base::PostTaskWithTraits(
         FROM_HERE,
-        base::TaskTraits()
-            .MayBlock()
-            .WithPriority(base::TaskPriority::BACKGROUND)
-            .WithShutdownBehavior(
-                base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN),
+        {MayBlock(), TaskPriority::BACKGROUND,
+         TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN},
         BindOnce(&TraceLog::ConvertTraceEventsToTraceFormat,
                  Passed(&previous_logged_events), flush_output_callback,
                  argument_filter_predicate));