Support REMB in combination with send-side BWE.

BUG=webrtc:4173

Review URL: https://codereview.webrtc.org/1581113006

Cr-Commit-Position: refs/heads/master@{#11322}
diff --git a/webrtc/modules/bitrate_controller/bitrate_controller_impl.h b/webrtc/modules/bitrate_controller/bitrate_controller_impl.h
index b601899..d7888cc 100644
--- a/webrtc/modules/bitrate_controller/bitrate_controller_impl.h
+++ b/webrtc/modules/bitrate_controller/bitrate_controller_impl.h
@@ -36,8 +36,9 @@
   RtcpBandwidthObserver* CreateRtcpBandwidthObserver() override;
 
   void SetStartBitrate(int start_bitrate_bps) override;
-  void SetMinMaxBitrate(int min_bitrate_bps,
-                                int max_bitrate_bps) override;
+  void SetMinMaxBitrate(int min_bitrate_bps, int max_bitrate_bps) override;
+
+  void UpdateDelayBasedEstimate(uint32_t bitrate_bps) override;
 
   void SetReservedBitrate(uint32_t reserved_bitrate_bps) override;