Reland of "Change TWCC send interval to reduce overhead on low BW situations."

webrtc/modules/congestion_controller/congestion_controller.cc

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 329 matching lines @@
   if (estimate_changed) {
     pacer_->SetEstimatedBitrate(bitrate_bps);
     probe_controller_->SetEstimatedBitrate(bitrate_bps);
     retransmission_rate_limiter_->SetMaxRate(bitrate_bps);
   }
 
   bitrate_bps = IsNetworkDown() || IsSendQueueFull() ? 0 : bitrate_bps;
 
   if (HasNetworkParametersToReportChanged(bitrate_bps, fraction_loss, rtt)) {
     observer_->OnNetworkChanged(bitrate_bps, fraction_loss, rtt);
+    remote_estimator_proxy_.OnBitrateChanged(bitrate_bps);
   }
 }
 
 bool CongestionController::HasNetworkParametersToReportChanged(
     uint32_t bitrate_bps,
     uint8_t fraction_loss,
     int64_t rtt) {
   rtc::CritScope cs(&critsect_);
   bool changed =
       last_reported_bitrate_bps_ != bitrate_bps ||
@@ skipping 12 matching lines @@
 bool CongestionController::IsSendQueueFull() const {
   return pacer_->ExpectedQueueTimeMs() > PacedSender::kMaxQueueLengthMs;
 }
 
 bool CongestionController::IsNetworkDown() const {
   rtc::CritScope cs(&critsect_);
   return network_state_ == kNetworkDown;
 }
 
 }  // namespace webrtc