Merge UpdateBandwidthEstimate with Update in AimdRateControl.

webrtc/modules/congestion_controller/delay_based_bwe.cc

Index: webrtc/modules/congestion_controller/delay_based_bwe.cc
diff --git a/webrtc/modules/congestion_controller/delay_based_bwe.cc b/webrtc/modules/congestion_controller/delay_based_bwe.cc
index e8d9d21050f21d1b931999b758979b95ec953bcb..709a5c7df5b14ef137df78bc8f6b7e37551ce4af 100644
--- a/webrtc/modules/congestion_controller/delay_based_bwe.cc
+++ b/webrtc/modules/congestion_controller/delay_based_bwe.cc
@@ -446,8 +446,7 @@ bool DelayBasedBwe::UpdateEstimate(int64_t arrival_time_ms,
   // TODO(terelius): RateControlInput::noise_var is deprecated and will be
   // removed. In the meantime, we set it to zero.
   const RateControlInput input(detector_.State(), acked_bitrate_bps, 0);
-  rate_control_.Update(&input, now_ms);
-  *target_bitrate_bps = rate_control_.UpdateBandwidthEstimate(now_ms);
+  *target_bitrate_bps = rate_control_.Update(&input, now_ms);
   return rate_control_.ValidEstimate();
 }