Expose time to on_logged_period in the AOS logger

This lets us know what time the logger just finished writing so we can
use that info in any callbacks.

Change-Id: Ic94f6bc60a9270111d5d5e2327dbadd85e8e01f5
Signed-off-by: James Kuszmaul <james.kuszmaul@bluerivertech.com>
diff --git a/aos/events/logging/log_writer.cc b/aos/events/logging/log_writer.cc
index 5ccf15b..56d0c4f 100644
--- a/aos/events/logging/log_writer.cc
+++ b/aos/events/logging/log_writer.cc
@@ -865,7 +865,7 @@
     LogUntil(std::min(last_synchronized_time_ + polling_period_, end_time));
 
     if (run_on_logged) {
-      on_logged_period_();
+      on_logged_period_(last_synchronized_time_);
     }
 
     // If we missed cycles, we could be pretty far behind.  Spin until we are