Move PacedSender ownership to RtpTransportControllerSend.

webrtc/call/rtp_transport_controller_send.cc

Index: webrtc/call/rtp_transport_controller_send.cc
diff --git a/webrtc/call/rtp_transport_controller_send.cc b/webrtc/call/rtp_transport_controller_send.cc
index b8b65a0d554dfbcba8fc48c37cb62536bf7b6c1f..937a9591765b33db65f691de74f6fc618cf3ea28 100644
--- a/webrtc/call/rtp_transport_controller_send.cc
+++ b/webrtc/call/rtp_transport_controller_send.cc
@@ -15,13 +15,17 @@ namespace webrtc {
 RtpTransportControllerSend::RtpTransportControllerSend(
     Clock* clock,
     webrtc::RtcEventLog* event_log)
-    : send_side_cc_(clock, nullptr /* observer */, event_log, &packet_router_) {
-}
+    : pacer_(clock, &packet_router_, event_log),
+      send_side_cc_(clock, nullptr /* observer */, event_log, &pacer_) {}
 
 PacketRouter* RtpTransportControllerSend::packet_router() {
   return &packet_router_;
 }
 
+PacedSender* RtpTransportControllerSend::pacer() {

[nisse-webrtc, 2017/08/18 06:19:18]

The packet_sender() method below returns the same object, but using an interface
type. I think this deserves a comment, with a brief explanation why this method
is needed, and whether or not we'll aim to delete it. If it's intended to stay,
I'd prefer to delete the other packet_sender method which becomes redundant.

[nisse-webrtc, 2017/08/18 07:14:33]

And yet another option for the return type is RtpPacketSender, which I attempted
to use in cl https://codereview.webrtc.org/2580843002/

[stefan-webrtc, 2017/08/22 07:37:53]

For now we need to return a PacedSender as we have to be able to register it to
the process thread. For that we could return a Module, but we're currently also
calling some methods on the PacedSender from the video streams. I think both
should be possible to get rid of later by adding a few methods to the
RtpTransportControllerSend instead of exposing the pacer directly.

+  return &pacer_;
+}
+
 SendSideCongestionController* RtpTransportControllerSend::send_side_cc() {
   return &send_side_cc_;
 }
@@ -32,7 +36,7 @@ RtpTransportControllerSend::transport_feedback_observer() {
 }
 
 RtpPacketSender* RtpTransportControllerSend::packet_sender() {
-  return send_side_cc_.pacer();
+  return &pacer_;
 }
 
 const RtpKeepAliveConfig& RtpTransportControllerSend::keepalive_config() const {