+++ This bug was initially created as a clone of Bug #1493860 +++ No need to update the spec over this, since we can absorb the absence of members easily enough in the constraints algorithm.

Well, we need to make sure the spec defines the behavior...

The spec's fitness distance algorithm [1] isn't specific enough to need updating, though it does rely on "present" [2], which means, if anything, it should be more correct with this change than before. In short, a constraint may be given in one of two forms, e.g. for a ConstrainDouble: [3] (double or ConstrainDoubleRange) ...where one form is a dictionary with only optional members. The absence of said optional members is equivalent to the constraint not being given (the default until bug 1368949), as far as the algorithm goes, by any meaningful interpretation. [1] https://w3c.github.io/mediacapture-main/getusermedia.html#dfn-fitness-distance [2] https://heycam.github.io/webidl/#dfn-present [3] https://w3c.github.io/mediacapture-main/getusermedia.html#idl-def-constraindouble

> though it does rely on "present" Perfect. That is exactly what's needed here.

Pushed by jbruaroey@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/336da65f35ea Remove dictionary null defaults from MediaTrackConstraintSet; handle absence in NormalizedConstraintSet. r=bzbarsky,pehrsons