Support stopping and starting logging at runtime

Change-Id: If1e1b7119808d1f56e96efb71ea7000e0fa13fe8
diff --git a/y2019/control_loops/drivetrain/drivetrain_replay.cc b/y2019/control_loops/drivetrain/drivetrain_replay.cc
index f7b69e4..98f3eeb 100644
--- a/y2019/control_loops/drivetrain/drivetrain_replay.cc
+++ b/y2019/control_loops/drivetrain/drivetrain_replay.cc
@@ -42,7 +42,8 @@
   log_writer_event_loop->SkipTimingReport();
   log_writer_event_loop->SkipAosLog();
   CHECK(nullptr == log_writer_event_loop->node());
-  aos::logger::Logger writer(FLAGS_output_file, log_writer_event_loop.get());
+  aos::logger::Logger writer(log_writer_event_loop.get());
+  writer.StartLoggingLocalNamerOnRun(FLAGS_output_file);
 
   std::unique_ptr<aos::EventLoop> drivetrain_event_loop =
       reader.event_loop_factory()->MakeEventLoop("drivetrain");