Add plot of network delay change computed based on transport feedback.

webrtc/modules/remote_bitrate_estimator/transport_feedback_adapter.h

Index: webrtc/modules/remote_bitrate_estimator/transport_feedback_adapter.h
diff --git a/webrtc/modules/remote_bitrate_estimator/transport_feedback_adapter.h b/webrtc/modules/remote_bitrate_estimator/transport_feedback_adapter.h
index 7e75112ed600b2b1964c577aaab976f9d353018d..b15185f4a2179b900e1cf8b6270ffb5158646aba 100644
--- a/webrtc/modules/remote_bitrate_estimator/transport_feedback_adapter.h
+++ b/webrtc/modules/remote_bitrate_estimator/transport_feedback_adapter.h
@@ -43,6 +43,9 @@ class TransportFeedbackAdapter : public TransportFeedbackObserver,
                  size_t length,
                  int probe_cluster_id) override;
   void OnSentPacket(uint16_t sequence_number, int64_t send_time_ms);
+
+  const std::vector<PacketInfo> GetPacketFeedbackVector(
+      const rtcp::TransportFeedback& feedback);
   void OnTransportFeedback(const rtcp::TransportFeedback& feedback) override;
 
   // Implements CallStatsObserver.