Rename variables to reflect that DelayBasedBwe lives on the send side rather than receive side.

webrtc/modules/congestion_controller/delay_based_bwe.h

Index: webrtc/modules/congestion_controller/delay_based_bwe.h
diff --git a/webrtc/modules/congestion_controller/delay_based_bwe.h b/webrtc/modules/congestion_controller/delay_based_bwe.h
index 7e2c8bdc524a37d1dd8d240c3ea90a3c728f1473..c5be7652324bb7f26c7fbbd5fe5bb21c90684ad2 100644
--- a/webrtc/modules/congestion_controller/delay_based_bwe.h
+++ b/webrtc/modules/congestion_controller/delay_based_bwe.h
@@ -65,11 +65,11 @@ class DelayBasedBwe {
   std::unique_ptr<InterArrival> inter_arrival_;
   std::unique_ptr<OveruseEstimator> estimator_;
   OveruseDetector detector_;
-  RateStatistics incoming_bitrate_;
+  RateStatistics receiver_incoming_bitrate_;
   int64_t last_update_ms_;
   int64_t last_seen_packet_ms_;
   bool uma_recorded_;
-  AimdRateControl remote_rate_;
+  AimdRateControl rate_control_;
   ProbeBitrateEstimator probe_bitrate_estimator_;
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(DelayBasedBwe);