Attach TransportFeedbackPacketLossTracker to ANA (PLR only)

webrtc/modules/congestion_controller/congestion_controller.cc

Index: webrtc/modules/congestion_controller/congestion_controller.cc
diff --git a/webrtc/modules/congestion_controller/congestion_controller.cc b/webrtc/modules/congestion_controller/congestion_controller.cc
index 3c349399ce7f66307ebcc43d72d923f46c6ea75b..6756aece0ff10c2f9c42560496d336553b75ffd3 100644
--- a/webrtc/modules/congestion_controller/congestion_controller.cc
+++ b/webrtc/modules/congestion_controller/congestion_controller.cc
@@ -262,6 +262,18 @@ RemoteBitrateEstimator* CongestionController::GetRemoteBitrateEstimator(
   }
 }
 
+void CongestionController::RegisterTransportFeedbackAdapterObserver(
+    TransportFeedbackAdapterObserver* observer) {
+  transport_feedback_adapter_.RegisterTransportFeedbackAdapterObserver(
+      observer);
+}
+
+void CongestionController::DeRegisterTransportFeedbackAdapterObserver(
+    TransportFeedbackAdapterObserver* observer) {
+  transport_feedback_adapter_.DeRegisterTransportFeedbackAdapterObserver(
+      observer);
+}
+
 RateLimiter* CongestionController::GetRetransmissionRateLimiter() {
   return retransmission_rate_limiter_.get();
 }
@@ -331,10 +343,12 @@ void CongestionController::Process() {
   MaybeTriggerOnNetworkChanged();
 }
 
-void CongestionController::AddPacket(uint16_t sequence_number,
+void CongestionController::AddPacket(uint32_t ssrc,
+                                     uint16_t sequence_number,
                                      size_t length,
                                      const PacedPacketInfo& pacing_info) {
-  transport_feedback_adapter_.AddPacket(sequence_number, length, pacing_info);
+  transport_feedback_adapter_.AddPacket(ssrc, sequence_number, length,
+                                        pacing_info);
 }
 
 void CongestionController::OnTransportFeedback(