Document Policy feature detection

[clelland]

For Permissions Policy, there is a policy object on the document and on iframes which can be used to inspect the active policy, or see the policies supported by the UA, and can indirectly be used to detect whether Permissions Policy is even supported at all.

Do we need something like that for Document Policy? A list of supported configuration points, and/or their current settings, or even a way in script to tell that Document Policy is available in the browser?

[annevk]

I'm actually wondering if we need it for Permissions Policy since there's also the Permissions API which could be used for most things instead.

[adhithyar]

Are there any plans for API that can be used to query for available document policies from JS? We would like to have this API to gracefully degrade if a specific policy is not available.