Opening this bug in response to: (In reply to Olli Pettay [:smaug] from Bug 1032839 comment #4) > Do we have a bug filed to convert RTCError to something sane. > (Use of __exposedProps__ is scary.) This refers to RTCError in PeerConnection.js: http://mxr.mozilla.org/mozilla-central/source/dom/media/PeerConnection.js#969 Actually, the spec calls for us to return DOMError as an argument to callbacks: http://dev.w3.org/2011/webrtc/editor/webrtc.html#rtcpeerconnectionerrorcallback The spec then has this note http://dev.w3.org/2011/webrtc/editor/webrtc.html#attributes-1 : > Ask the DOM team to extend their list with the following errors. > InvalidSessionDescriptionError > IncompatibleSessionDescriptionError > IncompatibleConstraintsError > IncompatibleMediaStreamTrackError > InternalError So it seems we are blocked on some extensions to DOMError or some discussion about this use of DOMError, as well as the outcome of DOMError (is it turning into DOMException?) - It seems weird to be creating and returning instances of DOMException as callback arguments rather than throwing them. For now, an improvement to the current __exposedProps__ code might be to make a temporary webidl-class that perhaps even inherits from DOMError and extends it? I think we're open to ideas.

Moved Part 1 from Bug 1091898 comment 48 here. Carrying forward r=bz (on irc), r=jesup.

Green try - https://treeherder.mozilla.org/ui/#/jobs?repo=try&revision=2ad4ee85e565