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 fd0d070ba0350c0801f0dbba3251225c8d623e38..81a4517984f73e8178ea7e379eeaff9791f5bedb 100644
--- a/webrtc/modules/congestion_controller/congestion_controller.cc
+++ b/webrtc/modules/congestion_controller/congestion_controller.cc
@@ -254,6 +254,18 @@ CongestionController::GetTransportFeedbackObserver() {
   return &transport_feedback_adapter_;
 }
 
+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();
 }