Change return type of CongestionController::pacer() method.

webrtc/call/call.cc

Index: webrtc/call/call.cc
diff --git a/webrtc/call/call.cc b/webrtc/call/call.cc
index 20daba88dfee9f71e9e57ea42801c01b3945fbd2..838bccc58d45645dcdd759ebf9cccce0ac705a1a 100644
--- a/webrtc/call/call.cc
+++ b/webrtc/call/call.cc
@@ -163,7 +163,6 @@ class Call : public webrtc::Call,
 
   const int num_cpu_cores_;
   const std::unique_ptr<ProcessThread> module_process_thread_;
-  const std::unique_ptr<ProcessThread> pacer_thread_;
   const std::unique_ptr<CallStats> call_stats_;
   const std::unique_ptr<BitrateAllocator> bitrate_allocator_;
   Call::Config config_;
@@ -259,7 +258,6 @@ Call::Call(const Call::Config& config)
     : clock_(Clock::GetRealTimeClock()),
       num_cpu_cores_(CpuInfo::DetectNumberOfCores()),
       module_process_thread_(ProcessThread::Create("ModuleProcessThread")),
-      pacer_thread_(ProcessThread::Create("PacerThread")),
       call_stats_(new CallStats(clock_)),
       bitrate_allocator_(new BitrateAllocator(this)),
       config_(config),
@@ -307,10 +305,6 @@ Call::Call(const Call::Config& config)
   module_process_thread_->Start();
   module_process_thread_->RegisterModule(call_stats_.get());
   module_process_thread_->RegisterModule(congestion_controller_.get());
-  pacer_thread_->RegisterModule(congestion_controller_->pacer());
-  pacer_thread_->RegisterModule(
-      congestion_controller_->GetRemoteBitrateEstimator(true));
-  pacer_thread_->Start();
 }
 
 Call::~Call() {
@@ -324,10 +318,6 @@ Call::~Call() {
   RTC_CHECK(video_receive_ssrcs_.empty());
   RTC_CHECK(video_receive_streams_.empty());
 
-  pacer_thread_->Stop();

[the sun, 2016/12/15 15:11:32]

Are there any subtle relationship issues between the CongestionController and
Call which may bite us, now that the pacer thread will keep running until after
the explicit dtor code? Do you need to
congestion_controller_.reset(nullptr);
?

[nisse-webrtc, 2016/12/16 09:38:13]

Don't know... Does the call object register any callbacks which are called on
the pacer thread?

[stefan-webrtc, 2016/12/22 09:54:58]

I don't think it does. It calls into rtp modules and transports, but not into
Call.

-  pacer_thread_->DeRegisterModule(congestion_controller_->pacer());
-  pacer_thread_->DeRegisterModule(
-      congestion_controller_->GetRemoteBitrateEstimator(true));
   module_process_thread_->DeRegisterModule(congestion_controller_.get());
   module_process_thread_->DeRegisterModule(call_stats_.get());
   module_process_thread_->Stop();