Revert of Remove SendPacer from ViEEncoder

webrtc/modules/bitrate_controller/bitrate_controller_impl.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 65 matching lines @@
   std::map<uint32_t, uint32_t> ssrc_to_last_received_extended_high_seq_num_;
   BitrateControllerImpl* owner_;
 };
 
 BitrateController* BitrateController::CreateBitrateController(
     Clock* clock,
     BitrateObserver* observer) {
   return new BitrateControllerImpl(clock, observer);
 }
 
-BitrateController* BitrateController::CreateBitrateController(Clock* clock) {
-  return new BitrateControllerImpl(clock, nullptr);
-}
-
 BitrateControllerImpl::BitrateControllerImpl(Clock* clock,
                                              BitrateObserver* observer)
     : clock_(clock),
       observer_(observer),
       last_bitrate_update_ms_(clock_->TimeInMilliseconds()),
       bandwidth_estimation_(),
       reserved_bitrate_bps_(0),
       last_bitrate_bps_(0),
       last_fraction_loss_(0),
       last_rtt_ms_(0),
       last_reserved_bitrate_bps_(0) {
-  // This calls the observer_ if set, which means that the observer provided by
-  // the user must be ready to accept a bitrate update when it constructs the
+  // This calls the observer_, which means that the observer provided by the
+  // user must be ready to accept a bitrate update when it constructs the
   // controller. We do this to avoid having to keep synchronized initial values
   // in both the controller and the allocator.
   MaybeTriggerOnNetworkChanged();
 }
 
 RtcpBandwidthObserver* BitrateControllerImpl::CreateRtcpBandwidthObserver() {
   return new RtcpBandwidthObserverImpl(this);
 }
 
 void BitrateControllerImpl::SetStartBitrate(int start_bitrate_bps) {
@@ skipping 83 matching lines @@
     int64_t now_ms) {
   {
     rtc::CritScope cs(&critsect_);
     bandwidth_estimation_.UpdateReceiverBlock(fraction_loss, rtt,
                                               number_of_packets, now_ms);
   }
   MaybeTriggerOnNetworkChanged();
 }
 
 void BitrateControllerImpl::MaybeTriggerOnNetworkChanged() {
-  if (!observer_)
-    return;
-
-  uint32_t bitrate_bps;
+  uint32_t bitrate;
   uint8_t fraction_loss;
   int64_t rtt;
-
-  if (GetNetworkParameters(&bitrate_bps, &fraction_loss, &rtt))
-    observer_->OnNetworkChanged(bitrate_bps, fraction_loss, rtt);
+  if (GetNetworkParameters(&bitrate, &fraction_loss, &rtt))
+    observer_->OnNetworkChanged(bitrate, fraction_loss, rtt);
 }
 
 bool BitrateControllerImpl::GetNetworkParameters(uint32_t* bitrate,
                                                  uint8_t* fraction_loss,
                                                  int64_t* rtt) {
   rtc::CritScope cs(&critsect_);
   int current_bitrate;
   bandwidth_estimation_.CurrentEstimate(&current_bitrate, fraction_loss, rtt);
   *bitrate = current_bitrate;
   *bitrate -= std::min(*bitrate, reserved_bitrate_bps_);
@@ skipping 21 matching lines @@
   bandwidth_estimation_.CurrentEstimate(&bitrate, &fraction_loss, &rtt);
   if (bitrate > 0) {
     bitrate = bitrate - std::min<int>(bitrate, reserved_bitrate_bps_);
     bitrate = std::max(bitrate, bandwidth_estimation_.GetMinBitrate());
     *bandwidth = bitrate;
     return true;
   }
   return false;
 }
 }  // namespace webrtc