Reverse |rtx_payload_types| map, and rename.

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 bd4b9976f698729c9337be38d38592379daa9527..18e904d076489fdddf99b667d6f37dd90c163fb2 100644
--- a/webrtc/call/video_receive_stream.h
+++ b/webrtc/call/video_receive_stream.h
@@ -168,14 +168,15 @@ class VideoReceiveStream {
       // Set if the stream is protected using FlexFEC.
       bool protected_by_flexfec = false;
 
-      // Map from video payload type (apt) -> RTX payload type (pt).
+      // Map from rtx payload type -> media payload type.
       // For RTX to be enabled, both an SSRC and this mapping are needed.
-      std::map<int, int> rtx_payload_types;
+      std::map<int, int> rtx_associated_payload_types;
       // TODO(nisse): This is a temporary accessor function to enable
       // reversing and renaming of the rtx_payload_types mapping.
       void AddRtxBinding(int rtx_payload_type, int media_payload_type) {
-        rtx_payload_types[media_payload_type] = rtx_payload_type;
+        rtx_associated_payload_types[rtx_payload_type] = media_payload_type;
       }
+
       // RTP header extensions used for the received stream.
       std::vector<RtpExtension> extensions;
     } rtp;