SSRC and RSID may only refer to one sink each in RtpDemuxer

webrtc/call/flexfec_receive_stream_impl.cc

Index: webrtc/call/flexfec_receive_stream_impl.cc
diff --git a/webrtc/call/flexfec_receive_stream_impl.cc b/webrtc/call/flexfec_receive_stream_impl.cc
index c73d9e98e59f55985821ef5be2b794f52b73aa26..9147040454d8557fd3f4f18b6a388659e129dda0 100644
--- a/webrtc/call/flexfec_receive_stream_impl.cc
+++ b/webrtc/call/flexfec_receive_stream_impl.cc
@@ -157,8 +157,9 @@ FlexfecReceiveStreamImpl::FlexfecReceiveStreamImpl(
   // problem too.
   rtp_stream_receiver_ =
       receiver_controller->CreateReceiver(config_.remote_ssrc, this);
-  for (uint32_t ssrc : config.protected_media_ssrcs)
-    receiver_controller->AddSink(ssrc, this);
+  for (uint32_t ssrc : config.protected_media_ssrcs) {
+    RTC_CHECK(receiver_controller->AddSink(ssrc, this));

[holmer, 2017/07/03 09:06:14]

Is it possible to trigger this by writing a broken SDP? In that case I think we
shouldn't CHECK but instead return an error. Hopefully this is verified earlier
in the stack though?

[eladalon, 2017/07/03 11:25:34]

As per our offline discussion, it would be better to first fix FlexFec to not
require being registered with the demuxer, and rebase this CL on top of it. I'll
do that.

+  }
 }
 
 FlexfecReceiveStreamImpl::~FlexfecReceiveStreamImpl() {