Restarting ICE

Hello folks,

speaking as contributor:
I believe we now have all the pieces we need to restart ICE properly, 
except for one little detail. Can we get this in, and close the book on 
ICE restart?

What's in:

- under setLocalDescription: "If a local description contains a 
different set of ICE credentials, then the ICE Agent must trigger an ICE 
restart." .... " If the local description was set with content that 
caused an ICE restart, then setconnection'sice gathering state 
<http://dev.w3.org/2011/webrtc/editor/webrtc.html#dom-peerconnection-ice-gathering-state>to|gathering|."

- in the description of the RTCIceConnectionState Enum: "(any state, ICE 
restart occurs): new"

The only remaining challenge is to get a local description with a 
different set of ICE credentials.
Since SDP mangling is just so last year, I suggest adding a constraint 
to the list in section 13.1 "Constraints":

RestartIce - this is an enum type constraint that can take the values 
"true" and "false". The default is a non-mandatory "false".
When the value of the constraint is mandatory "true", the generated 
description will have ICE credentials that are different from the 
current credentials (as visible in the localDescription attribute's 
SDP). Applying the generated description will restart ICE.
When the value of the constraint is mandatory "false", and the 
localDescription attribute has valid ICE credentials, the generated 
description will have the same ICE credentials as the current value from 
the LocalDescription attribute.
When the constraint is optional, the implementation may choose to 
generate new credentials or not based on other criteria.

If this is non-controversial, can we "just add it"?
If it is controversial - what's the controversy?

          Harald