Adding a delay line to NetEq's output

This change adds an optional delay to NetEq's output. Note, this is not
equivalent to increasing the jitter buffer with the same extra length.

Bug: b/156734419
Change-Id: I8b70b6b3bffcfd3da296ccf29853864baa03d6bb
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/175110
Commit-Queue: Henrik Lundin <henrik.lundin@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31343}

modules/audio_coding/neteq/tools/neteq_test.cc

@@ -91,7 +91,8 @@ int64_t NetEqTest::Run() {
     simulation_time += step_result.simulation_step_ms;
   } while (!step_result.is_simulation_finished);
   if (callbacks_.simulation_ended_callback) {
-    callbacks_.simulation_ended_callback->SimulationEnded(simulation_time);
+    callbacks_.simulation_ended_callback->SimulationEnded(simulation_time,
+                                                          neteq_.get());
   }
   return simulation_time;
 }