Remove GetFeedbackInterval in sender side BWE.

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 6e7a6f8d63a654e078f41127b6919263f182df07..d2b5b3cbdb66e4ef944428e6897e604dc6641056 100644
--- a/webrtc/modules/congestion_controller/delay_based_bwe.h
+++ b/webrtc/modules/congestion_controller/delay_based_bwe.h
@@ -76,13 +76,15 @@ class DelayBasedBwe {
     float bitrate_estimate_var_;
     RateStatistics old_estimator_;
     const bool in_experiment_;
+    bool last_result_was_valid_;
   };
 
   Result IncomingPacketInfo(const PacketInfo& info);
+
+  void MaybeUpdateEstimate(Result* result);
   // Updates the current remote rate estimate and returns true if a valid
   // estimate exists.
-  bool UpdateEstimate(int64_t packet_arrival_time_ms,
-                      int64_t now_ms,
+  bool UpdateEstimate(int64_t now_ms,
                       rtc::Optional<uint32_t> acked_bitrate_bps,
                       uint32_t* target_bitrate_bps);
   const bool in_trendline_experiment_;
@@ -96,7 +98,6 @@ class DelayBasedBwe {
   std::unique_ptr<MedianSlopeEstimator> median_slope_estimator_;
   OveruseDetector detector_;
   BitrateEstimator receiver_incoming_bitrate_;
-  int64_t last_update_ms_;
   int64_t last_seen_packet_ms_;
   bool uma_recorded_;
   AimdRateControl rate_control_;