From 1dc10ff725cdbbe7aa72684cc768e2b7beac21f8 Mon Sep 17 00:00:00 2001
From: Jan-Ivar Bruaroey
[= underlying data transport =] was closed.
+ Let connection be the {{RTCPeerConnection}} object + associated with channel. +
+Remove channel from connection.{{RTCPeerConnection/[[DataChannels]]}}.