Deal with failure to create remote streams and tracks.

[ekr]

                                               mRemoteRequestedSDP);

if (NS_FAILED(nrv)) {
Error error;
switch (nrv) {
case NS_ERROR_INVALID_ARG: error = kInvalidSessionDescription; break;
case NS_ERROR_UNEXPECTED: error = kInvalidState; break;
default: error = kInternalError;
}

std::string error_string = mJsepSession->last_error();
// appendSdpParseErrors(mSDPParseErrorMessages, &error_string, &error);
CSFLogError(logTag, "%s: pc = %s, error = %s",
            __FUNCTION__, mHandle.c_str(), error_string.c_str());
pco->OnSetRemoteDescriptionError(error, ObString(error_string.c_str()), rv);

} else {
// All the stream stuff is a mess here. We just have one stream
// but a pile of tracks.
// Step 1. Verify that we have a stream.
nsRefPtrsipcc::RemoteSourceStreamInfo info;
if (mMedia->RemoteStreamsLength() < 1) {
nsresult rv = CreateRemoteSourceStreamInfo(&info);
if (NS_FAILED(rv)) {
MOZ_CRASH(); // TODO([email protected]): How do we recover here? We don't
// want mismatches.
}

  rv = mMedia->AddRemoteStream(info);
  if (NS_FAILED(rv)) {
    MOZ_CRASH();  // TODO([email protected]): How do we recover here? We don't
                  // want mismatches.
  }
} else {
  info = mMedia->GetRemoteStream(0);
}
DOMMediaStream* stream = info->GetMediaStream();

// Step 2. Add the tracks. Unfortunately, we only can really support
// two tracks, one audio and one video.
nsresult rv;
size_t num_tracks = mJsepSession->num_remote_tracks();
MOZ_ASSERT(num_tracks <= 2);
for (size_t i = 0; i < num_tracks; ++i) {
  RefPtr<JsepMediaStreamTrack> track;
  rv = mJsepSession->remote_track(i, &track);
  if (NS_FAILED(rv)) {
    MOZ_CRASH();  // TODO([email protected]): How do we recover here? We don't
                  // want mismatches.
  }
  if (track->media_type() == mozilla::SdpMediaSection::kAudio) {
    info->mTrackTypeHints |= DOMMediaStream::HINT_CONTENTS_AUDIO;
  } else if (track->media_type() == mozilla::SdpMediaSection::kAudio) {
    info->mTrackTypeHints |= DOMMediaStream::HINT_CONTENTS_AUDIO;
  } else {
    // Data channel?
  }
}