Let PacketRouter separate send and receive modules.

This is in preparation for merging the ViERemb logic in packet_router,
to send REMB feedback as sender reports if possible, otherwise as
receiver reports.

BUG=webrtc:7135

Review-Url: https://codereview.webrtc.org/2774623006
Cr-Original-Commit-Position: refs/heads/master@{#17489}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: fdbfdc9786de5ec50ff750e5a61c3d39524e24bb
diff --git a/video/rtp_stream_receiver.cc b/video/rtp_stream_receiver.cc
index a7fdb28..90dd0da 100644
--- a/video/rtp_stream_receiver.cc
+++ b/video/rtp_stream_receiver.cc
@@ -115,7 +115,7 @@
       complete_frame_callback_(complete_frame_callback),
       keyframe_request_sender_(keyframe_request_sender),
       timing_(timing) {
-  packet_router_->AddRtpModule(rtp_rtcp_.get());
+  packet_router_->AddReceiveRtpModule(rtp_rtcp_.get());
   rtp_receive_statistics_->RegisterRtpStatisticsCallback(receive_stats_proxy);
   rtp_receive_statistics_->RegisterRtcpStatisticsCallback(receive_stats_proxy);
 
@@ -202,7 +202,7 @@
 
   process_thread_->DeRegisterModule(rtp_rtcp_.get());
 
-  packet_router_->RemoveRtpModule(rtp_rtcp_.get());
+  packet_router_->RemoveReceiveRtpModule(rtp_rtcp_.get());
   rtp_rtcp_->SetREMBStatus(false);
   if (config_.rtp.remb) {
     remb_->RemoveReceiveChannel(rtp_rtcp_.get());