[Feature Policy] Should (sensorless) "inline" "viewer" sessions be allowed without the XR policy-controlled feature?

[ddorwin]

[This is one of the decisions to make as part of resolving #308 and #729.]

There shouldn't be any privacy concerns for "inline" sessions using the "viewer" reference space. Should it be possible for applications to create such sessions and reference spaces without any WebXR-related policy-controlled feature enabled (i.e., without "xr" or "vr") or should it not be possible to successfully request any session without a/the "base" feature enabled?

[ddorwin]

The outcome of #308 is that all features included in "VR complete" are controlled by "xr". Thus, the answer to this question is "no."

/agenda to discuss this along with #730 - see that issue for more details.

[toji]

Nell and I talked this over again today, and the general response that we came to was that polyfilling is an appropriate way to address scenarios where a developer wants inline, sensorless XR access in an environment where everything else is blocked. It allows for a significantly cleaner feature policy as well.