Attach TransportFeedbackPacketLossTracker to ANA (PLR only)

webrtc/modules/rtp_rtcp/source/rtp_sender.cc

Index: webrtc/modules/rtp_rtcp/source/rtp_sender.cc
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_sender.cc b/webrtc/modules/rtp_rtcp/source/rtp_sender.cc
index add7c21e9be22e109c15227de2b7ee0ac4336c7f..925af5f4f707b10de9d4ae3a1ac283f906ed6878 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_sender.cc
+++ b/webrtc/modules/rtp_rtcp/source/rtp_sender.cc
@@ -1264,7 +1264,12 @@ void RTPSender::AddPacketToTransportFeedback(uint16_t packet_id,
   }
 
   if (transport_feedback_observer_) {
-    transport_feedback_observer_->AddPacket(packet_id, packet_size,
+    uint32_t ssrc;
+    {
+      rtc::CritScope lock(&send_critsect_);
+      ssrc = ssrc_;
+    }
+    transport_feedback_observer_->AddPacket(ssrc, packet_id, packet_size,
                                             probe_cluster_id);
   }
 }