Introduce interfaces for compressing and decompressing log files

Change-Id: Ia7da3f840a1780a04203f1c312447b50b142a5a3
diff --git a/aos/events/logging/log_edit.cc b/aos/events/logging/log_edit.cc
index 4078f9b..9961bd8 100644
--- a/aos/events/logging/log_edit.cc
+++ b/aos/events/logging/log_edit.cc
@@ -38,7 +38,8 @@
       aos::logger::SpanReader span_reader(orig_path);
       CHECK(!span_reader.ReadMessage().empty()) << ": Empty header, aborting";
 
-      aos::logger::DetachedBufferWriter buffer_writer(FLAGS_logfile);
+      aos::logger::DetachedBufferWriter buffer_writer(
+          FLAGS_logfile, std::make_unique<aos::logger::DummyEncoder>());
       buffer_writer.QueueSizedFlatbuffer(&fbb);
 
       while (true) {
@@ -47,7 +48,7 @@
           break;
         }
 
-        buffer_writer.WriteSizedFlatbuffer(msg_data);
+        buffer_writer.QueueSpan(msg_data);
       }
     } else {
       aos::logger::MessageReader reader(FLAGS_logfile);