Delete member VideoReceiveStream::Config::Rtp::ulpfec.

Replaced with scalars ulpfec_payload_type and red_payload_type.

In particular, ulpfec.red_rtx_payload_type, which duplicated info in
rtx_associated_payload_types, is deleted. This is a followup to cl
https://codereview.webrtc.org/3012963002.

BUG=webrtc:7135

Review-Url: https://codereview.webrtc.org/3019453002
Cr-Commit-Position: refs/heads/master@{#19965}
diff --git a/call/video_receive_stream.h b/call/video_receive_stream.h
index 7d996ab..de6f712 100644
--- a/call/video_receive_stream.h
+++ b/call/video_receive_stream.h
@@ -166,13 +166,9 @@
       // See NackConfig for description.
       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;
+      // Payload types for ULPFEC and RED, respectively.
+      int ulpfec_payload_type = -1;
+      int red_payload_type = -1;
 
       // SSRC for retransmissions.
       uint32_t rtx_ssrc = 0;