Pass time constant to bwe smoothing filter.

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 6aab54918cb09829b46c42b41c30929c8dca0757..f5a7b209d841402d9a5064889f1308c55d17e808 100644
--- a/webrtc/modules/congestion_controller/delay_based_bwe.h
+++ b/webrtc/modules/congestion_controller/delay_based_bwe.h
@@ -20,6 +20,7 @@
 #include "webrtc/base/rate_statistics.h"
 #include "webrtc/base/thread_checker.h"
 #include "webrtc/modules/congestion_controller/probe_bitrate_estimator.h"
+#include "webrtc/modules/congestion_controller/probing_interval_estimator.h"
 #include "webrtc/modules/remote_bitrate_estimator/aimd_rate_control.h"
 #include "webrtc/modules/remote_bitrate_estimator/include/remote_bitrate_estimator.h"
 #include "webrtc/modules/remote_bitrate_estimator/inter_arrival.h"
@@ -50,6 +51,7 @@ class DelayBasedBwe {
   bool LatestEstimate(std::vector<uint32_t>* ssrcs,
                       uint32_t* bitrate_bps) const;
   void SetMinBitrate(int min_bitrate_bps);
+  int64_t GetProbingIntervalMs() const;
 
  private:
   // Computes a bayesian estimate of the throughput given acks containing
@@ -93,6 +95,7 @@ class DelayBasedBwe {
   bool uma_recorded_;
   AimdRateControl rate_control_;
   ProbeBitrateEstimator probe_bitrate_estimator_;
+  ProbingIntervalEstimator probing_interval_estimator_;
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(DelayBasedBwe);
 };