Break out pacer thread from CongestionController to increase testability.

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 129 matching lines @@
     RemoteBitrateObserver* remote_bitrate_observer)
     : clock_(clock),
       pacer_(new PacedSender(clock_,
              &packet_router_,
              BitrateController::kDefaultStartBitrateKbps,
              PacedSender::kDefaultPaceMultiplier *
                  BitrateController::kDefaultStartBitrateKbps,
              0)),
       remote_bitrate_estimator_(
           new WrappingBitrateEstimator(remote_bitrate_observer, clock_)),
-      pacer_thread_(ProcessThread::Create("PacerThread")),
       // Constructed last as this object calls the provided callback on
       // construction.
       bitrate_controller_(
           BitrateController::CreateBitrateController(clock_, bitrate_observer)),
       remote_estimator_proxy_(clock_, &packet_router_),
       transport_feedback_adapter_(bitrate_controller_.get(), clock_),
       min_bitrate_bps_(RemoteBitrateEstimator::kDefaultMinBitrateBps) {
   transport_feedback_adapter_.SetBitrateEstimator(
       new RemoteBitrateEstimatorAbsSendTime(&transport_feedback_adapter_,
                                             clock_));
   transport_feedback_adapter_.GetBitrateEstimator()->SetMinBitrate(
       min_bitrate_bps_);
-  pacer_thread_->RegisterModule(pacer_.get());
-  pacer_thread_->RegisterModule(&remote_estimator_proxy_);
-  pacer_thread_->Start();
 }
 
 CongestionController::~CongestionController() {
-  pacer_thread_->Stop();
-  pacer_thread_->DeRegisterModule(pacer_.get());
-  pacer_thread_->DeRegisterModule(&remote_estimator_proxy_);
 }
 
 
 void CongestionController::SetBweBitrates(int min_bitrate_bps,
                                           int start_bitrate_bps,
                                           int max_bitrate_bps) {
   RTC_DCHECK(config_thread_checker_.CalledOnValidThread());
   // TODO(holmer): We should make sure the default bitrates are set to 10 kbps,
   // and that we don't try to set the min bitrate to 0 from any applications.
   // The congestion controller should allow a min bitrate of 0.
@@ skipping 66 matching lines @@
                   remote_bitrate_estimator_->TimeUntilNextProcess());
 }
 
 int32_t CongestionController::Process() {
   bitrate_controller_->Process();
   remote_bitrate_estimator_->Process();
   return 0;
 }
 
 }  // namespace webrtc