Add GetSources to VideoRtpReceiver

BUG=webrtc:9770

Change-Id: I16143fce6eb727bbab0f6c621aa5b51bc6d28d6b
Reviewed-on: https://webrtc-review.googlesource.com/101600
Reviewed-by: Seth Hampson <shampson@webrtc.org>
Reviewed-by: Åsa Persson <asapersson@webrtc.org>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Commit-Queue: Jonas Oreland <jonaso@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24858}
diff --git a/call/video_receive_stream.h b/call/video_receive_stream.h
index 395a3d2..b5c1649 100644
--- a/call/video_receive_stream.h
+++ b/call/video_receive_stream.h
@@ -19,6 +19,7 @@
 #include "api/call/transport.h"
 #include "api/rtp_headers.h"
 #include "api/rtpparameters.h"
+#include "api/rtpreceiverinterface.h"
 #include "api/video/video_content_type.h"
 #include "api/video/video_sink_interface.h"
 #include "api/video/video_timing.h"
@@ -239,6 +240,8 @@
   virtual void AddSecondarySink(RtpPacketSinkInterface* sink) = 0;
   virtual void RemoveSecondarySink(const RtpPacketSinkInterface* sink) = 0;
 
+  virtual std::vector<RtpSource> GetSources() const = 0;
+
  protected:
   virtual ~VideoReceiveStream() {}
 };