Fix ability to subclass LogReader

Change-Id: I1afbf5246d47eaa65531f5ec74a1480ad93ff899
Signed-off-by: Austin Schuh <austin.schuh@bluerivertech.com>
Signed-off-by: James Kuszmaul <james.kuszmaul@bluerivertech.com>
diff --git a/aos/events/logging/log_reader.h b/aos/events/logging/log_reader.h
index f9616ab..f25f1f6 100644
--- a/aos/events/logging/log_reader.h
+++ b/aos/events/logging/log_reader.h
@@ -102,7 +102,7 @@
   LogReader(LogFilesContainer log_files,
             const Configuration *replay_configuration = nullptr,
             const ReplayChannels *replay_channels = nullptr);
-  ~LogReader();
+  virtual ~LogReader();
 
   // Registers all the callbacks to send the log file data out on an event loop
   // created in event_loop_factory.  This also updates time to be at the start
@@ -115,7 +115,8 @@
   // Registers all the callbacks to send the log file data out to an event loop
   // factory.  This does not start replaying or change the current distributed
   // time of the factory.  It does change the monotonic clocks to be right.
-  void RegisterWithoutStarting(SimulatedEventLoopFactory *event_loop_factory);
+  virtual void RegisterWithoutStarting(
+      SimulatedEventLoopFactory *event_loop_factory);
   // Runs the log until the last start time.  Register above is defined as:
   // Register(...) {
   //   RegisterWithoutStarting