WebKit should raise InvalidStateError, not InvalidAccessError if user gesture is missing for getDisplayMedia according to the spec.
If the relevant global object of this does not have transient activation, return a promise rejected with a DOMException object whose name attribute has the value InvalidStateError.
I believe this should fix it: https://github.com/WebKit/WebKit/compare/main...beaufortfrancois:WebKit:patch-1
Do you want to make a PR, or should we take over?
Please take over ;)