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/call/congestion_controller.cc b/webrtc/call/congestion_controller.cc
index 4030f8e..0267d79 100644
--- a/webrtc/call/congestion_controller.cc
+++ b/webrtc/call/congestion_controller.cc
@@ -237,8 +237,7 @@
 CongestionController::GetTransportFeedbackObserver() {
   if (transport_feedback_adapter_.get() == nullptr) {
     transport_feedback_adapter_.reset(new TransportFeedbackAdapter(
-        bitrate_controller_->CreateRtcpBandwidthObserver(),
-        Clock::GetRealTimeClock(), process_thread_));
+        bitrate_controller_.get(), Clock::GetRealTimeClock(), process_thread_));
     transport_feedback_adapter_->SetBitrateEstimator(
         new RemoteBitrateEstimatorAbsSendTime(
             transport_feedback_adapter_.get(), Clock::GetRealTimeClock()));