Make RTX pt/apt reconfigurable by calling WebRtcVideoChannel2::SetRecvParameters.

webrtc/video_receive_stream.h

Index: webrtc/video_receive_stream.h
diff --git a/webrtc/video_receive_stream.h b/webrtc/video_receive_stream.h
index 3a0c358bb924016fbe93fecf8e62b19691371488..8f6a24aba4598fc413e0cfadf105a66db5872f9a 100644
--- a/webrtc/video_receive_stream.h
+++ b/webrtc/video_receive_stream.h
@@ -116,6 +116,7 @@ class VideoReceiveStream {
 
       // Synchronization source (stream identifier) to be received.
       uint32_t remote_ssrc = 0;
+
       // Sender SSRC used for sending RTCP (such as receiver reports).
       uint32_t local_ssrc = 0;
 
@@ -141,19 +142,12 @@ class VideoReceiveStream {
       // See UlpfecConfig for description.
       UlpfecConfig ulpfec;
 
-      // RTX settings for incoming video payloads that may be received. RTX is
-      // disabled if there's no config present.
-      struct Rtx {
-        // SSRCs to use for the RTX streams.
-        uint32_t ssrc = 0;
-
-        // Payload type to use for the RTX stream.
-        int payload_type = 0;
-      };
+      // SSRC for retransmissions.
+      uint32_t rtx_ssrc = 0;
 
-      // Map from video RTP payload type -> RTX config.
-      typedef std::map<int, Rtx> RtxMap;
-      RtxMap rtx;
+      // Map from video payload type (apt) -> RTX payload type (pt).
+      // RTX is disabled if no mapping is given here.
+      std::map<int, int> rtx_payload_types;
 
       // RTP header extensions used for the received stream.
       std::vector<RtpExtension> extensions;