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

webrtc/modules/congestion_controller/include/congestion_controller.h

Index: webrtc/modules/congestion_controller/include/congestion_controller.h
diff --git a/webrtc/modules/congestion_controller/include/congestion_controller.h b/webrtc/modules/congestion_controller/include/congestion_controller.h
index 004a84752eefe4f063d06850519074fef2d4dd1a..c17e3de4d1dee33f39cee9d28107e9d96927cade 100644
--- a/webrtc/modules/congestion_controller/include/congestion_controller.h
+++ b/webrtc/modules/congestion_controller/include/congestion_controller.h
@@ -81,9 +81,9 @@ class CongestionController : public CallStatsObserver, public Module {
   virtual RemoteBitrateEstimator* GetRemoteBitrateEstimator(
       bool send_side_bwe);
   virtual int64_t GetPacerQueuingDelayMs() const;
-  // TODO(nisse): Delete this accessor function. The pacer should be
-  // internal to the congestion controller.
-  virtual PacedSender* pacer() { return pacer_.get(); }
+  // TODO(nisse): Rename or delete this accessor function. The pacer
+  // should be internal to the congestion controller.
+  virtual RtpPacketSender* pacer() { return pacer_.get(); }
   virtual TransportFeedbackObserver* GetTransportFeedbackObserver();
   RateLimiter* GetRetransmissionRateLimiter();
   void EnablePeriodicAlrProbing(bool enable);
@@ -121,6 +121,8 @@ class CongestionController : public CallStatsObserver, public Module {
   Clock* const clock_;
   Observer* const observer_;
   PacketRouter* const packet_router_;
+  // TODO(nisse): Convert to TaskQueue.

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

Yes, please!

+  const std::unique_ptr<ProcessThread> pacer_thread_;
   const std::unique_ptr<PacedSender> pacer_;
   const std::unique_ptr<RemoteBitrateEstimator> remote_bitrate_estimator_;
   const std::unique_ptr<BitrateController> bitrate_controller_;