Revert of Delete Rtx-related methods from RTPPayloadRegistry.

webrtc/video/rtp_video_stream_receiver.cc

Index: webrtc/video/rtp_video_stream_receiver.cc
diff --git a/webrtc/video/rtp_video_stream_receiver.cc b/webrtc/video/rtp_video_stream_receiver.cc
index 5aff22633b4e312c00d0bf3c544a2c00007dba6e..1dbd86988d30df5d655be795b23e6bcefba4f54f 100644
--- a/webrtc/video/rtp_video_stream_receiver.cc
+++ b/webrtc/video/rtp_video_stream_receiver.cc
@@ -453,7 +453,7 @@
                                            size_t packet_length,
                                            const RTPHeader& header,
                                            bool in_order) {
-  if (rtp_payload_registry_.IsRed(header)) {
+  if (rtp_payload_registry_.IsEncapsulated(header)) {
     ParseAndHandleEncapsulatingHeader(packet, packet_length, header);
     return;
   }
@@ -485,6 +485,8 @@
       return;
     }
     ulpfec_receiver_->ProcessReceivedFec();
+  } else if (rtp_payload_registry_.IsRtx(header)) {
+    LOG(LS_WARNING) << "Unexpected RTX packet on media ssrc";
   }
 }