Add RemoteEstimatorProxy for capturing receive times

webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.cc

Index: webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.cc
diff --git a/webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.cc b/webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.cc
index fee634b383af4310f94042c544fff63ff2448884..975d3f30bc87fc23087105407fd836e933187b21 100644
--- a/webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.cc
+++ b/webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.cc
@@ -304,6 +304,13 @@ void TransportFeedback::WithMediaSourceSsrc(uint32_t ssrc) {
   media_source_ssrc_ = ssrc;
 }
 
+uint32_t TransportFeedback::GetPacketSenderSsrc() const {
+  return packet_sender_ssrc_;
+}
+
+uint32_t TransportFeedback::GetMediaSourceSsrc() const {
+  return media_source_ssrc_;
+}
 void TransportFeedback::WithBase(uint16_t base_sequence,
                                  int64_t ref_timestamp_us) {
   DCHECK_EQ(-1, base_seq_);