Delete RtpVideoStreamReceiver methods GetRtpReceiver and rtp_rtcp

Replaced by new method GetSyncInfo.

Bug: webrtc:7135
Change-Id: I541567a5ca173dc334fd85e83f15b25a3120b8aa
Reviewed-on: https://webrtc-review.googlesource.com/91123
Commit-Queue: Niels Moller <nisse@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24148}

video/rtp_video_stream_receiver.h

@@ -18,6 +18,7 @@
 #include <vector>
 
 #include "call/rtp_packet_sink_interface.h"
+#include "call/syncable.h"
 #include "call/video_receive_stream.h"
 #include "modules/include/module_common_types.h"
 #include "modules/rtp_rtcp/include/receive_statistics.h"
@@ -75,12 +76,13 @@ class RtpVideoStreamReceiver : public RtpData,
 
   bool AddReceiveCodec(const VideoCodec& video_codec,
                        const std::map<std::string, std::string>& codec_params);
-  RtpReceiver* GetRtpReceiver() const;
-  RtpRtcp* rtp_rtcp() const { return rtp_rtcp_.get(); }
 
   void StartReceive();
   void StopReceive();
 
+  // Produces the transport-related timestamps; current_delay_ms is left unset.
+  absl::optional<Syncable::Info> GetSyncInfo() const;
+
   bool DeliverRtcp(const uint8_t* rtcp_packet, size_t rtcp_packet_length);
 
   void FrameContinuous(int64_t seq_num);