Queue messages in LogReader::State

This gives us an interface to run the noncausal time offset filter.

Change-Id: I251714f3a6bcd78dd5cae8fd7089ca078e1663c4
diff --git a/aos/events/logging/logfile_utils.h b/aos/events/logging/logfile_utils.h
index 23dadc8..2b08b59 100644
--- a/aos/events/logging/logfile_utils.h
+++ b/aos/events/logging/logfile_utils.h
@@ -570,7 +570,7 @@
   // Everything else needs the node set before it works.
 
   // Returns a timestamp for the oldest message in this group of logfiles.
-  monotonic_clock::time_point OldestMessage() const;
+  monotonic_clock::time_point OldestMessageTime() const;
   // Pops the oldest message.
   std::tuple<TimestampMerger::DeliveryTimestamp, int,
              FlatbufferVector<MessageHeader>>