Reland of Use RtxReceiveStream.

webrtc/call/video_receive_stream.h

Index: webrtc/call/video_receive_stream.h
diff --git a/webrtc/call/video_receive_stream.h b/webrtc/call/video_receive_stream.h
index e51184e2dd524ba0b96c4858602ae222a791c775..f199ca1f851dac7ae89b79ca9680bf22cc75e817 100644
--- a/webrtc/call/video_receive_stream.h
+++ b/webrtc/call/video_receive_stream.h
@@ -167,6 +167,11 @@ class VideoReceiveStream {
       NackConfig nack;
 
       // See UlpfecConfig for description.
+      // TODO(nisse): UlpfecConfig includes the field red_rtx_payload_type,
+      // which duplicates info in the rtx_associated_payload_types mapping. So
+      // delete the use of UlpfecConfig here, and replace by the values which
+      // make sense in this context, likely those are ulpfec_payload_type_ and
+      // red_payload_type_.
       UlpfecConfig ulpfec;
 
       // SSRC for retransmissions.