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_stats_plotter.h

@@ -28,7 +28,7 @@ class NetEqStatsPlotter : public NetEqSimulationEndedCallback {
                     bool show_concealment_events,
                     std::string base_file_name);
 
-  void SimulationEnded(int64_t simulation_time_ms) override;
+  void SimulationEnded(int64_t simulation_time_ms, NetEq* neteq) override;
 
   NetEqStatsGetter* stats_getter() { return stats_getter_.get(); }