Help Wantedcssom-view-1topic: multiple globals
描述
https://drafts.csswg.org/cssom-view/#web-exposed-screen-area
In the case of using the "viewport", it's not defined which viewport that is. Probably need to say "for a browsing context" or so, and pass in a browsing context everywhere that uses this term.
That browsing context likely should be the top-level browsing context. It would not make much sense for window.open() in an <iframe> to be sized after the <iframe>'s viewport; it should be sized after the top-level browsing context (even if that is cross-origin, I think -- it's already possible to follow a link with target _top and check dimensions you get, so it's not exposing new information across origins).