Refactor NACK bitrate allocation

webrtc/modules/congestion_controller/include/congestion_controller.h

Index: webrtc/modules/congestion_controller/include/congestion_controller.h
diff --git a/webrtc/modules/congestion_controller/include/congestion_controller.h b/webrtc/modules/congestion_controller/include/congestion_controller.h
index 82906efc1d98d228bbddd13e37814315e7dcc137..07915898fe092f16a5ff52c519ce3f47f42347ea 100644
--- a/webrtc/modules/congestion_controller/include/congestion_controller.h
+++ b/webrtc/modules/congestion_controller/include/congestion_controller.h
@@ -32,6 +32,7 @@ class BitrateController;
 class BitrateObserver;
 class Clock;
 class ProcessThread;
+class RateLimiter;
 class RemoteBitrateEstimator;
 class RemoteBitrateObserver;
 class TransportFeedbackObserver;
@@ -83,6 +84,7 @@ class CongestionController : public CallStatsObserver, public Module {
   virtual PacedSender* pacer() { return pacer_.get(); }
   virtual PacketRouter* packet_router() { return packet_router_.get(); }
   virtual TransportFeedbackObserver* GetTransportFeedbackObserver();
+  RateLimiter* GetRetransmissionRateLimiter();
 
   // SetAllocatedSendBitrateLimits sets bitrates limits imposed by send codec
   // settings.
@@ -121,6 +123,7 @@ class CongestionController : public CallStatsObserver, public Module {
   const std::unique_ptr<PacedSender> pacer_;
   const std::unique_ptr<RemoteBitrateEstimator> remote_bitrate_estimator_;
   const std::unique_ptr<BitrateController> bitrate_controller_;
+  const std::unique_ptr<RateLimiter> retransmission_rate_limiter_;
   RemoteEstimatorProxy remote_estimator_proxy_;
   TransportFeedbackAdapter transport_feedback_adapter_;
   int min_bitrate_bps_;