Convert ControlLoop over to using EventLoop

Next step is to pass in the event loop and flip over to using it in
tests and at runtime.

Change-Id: Ia3b8f099e4eacc0ffa8fbfe00d651f3684a8c783
diff --git a/aos/events/shm-event-loop.cc b/aos/events/shm-event-loop.cc
index 6231df2..b05aa84 100644
--- a/aos/events/shm-event-loop.cc
+++ b/aos/events/shm-event-loop.cc
@@ -218,6 +218,8 @@
 void ShmEventLoop::Run() {
   set_is_running(true);
   for (const auto &run : on_run_) run();
+  // TODO(austin): epoll event loop in main thread (if needed), and async safe
+  // quit handler.
   thread_state_->Run();
 }