Chris Harrelson

@bgirard, a question: is it just images in the viewport that you want to check for download+render? If so, why does a regular IntersectionObserver on them not work? Also, does...

> What are the performance implications of calling `querySelecterAll` on an ancestor of an invisible subtree for different selector? I filed #144 which may be useful to guide web authors...

I take back my previous comment, it was just incorrect. querySelectorAll does not force-compute styles.

Another use case: determining whether a `subtree-visibility: hidden` element has its subtree skipped. AMP saw this use case when testing with hidden-matchable. They wanted a notification that state changed on...

Update: the previous use case about detecting subtree skipping turned out to be only for a specific AMP component, and was able to be achieved in a different way. The...

@vmpstr raised a very good point, which is that, since `contain:size` depends on whether or not contents are skipped, any attempt to use something other than a direct signal of...

New use case: detecting whether an iframe embedded in a cross-origin, possibly not trusted, context is hidden. The iframe would reasonably want to know whether it is hidden, so that...

@developit yes, if we decided that iframes received page visibilty lifecycle events when hidden by `content-visibility`. Right now they don't...

I think we should definitely let `renderPriority` affect iframes, since some content needs to be put in iframes and it's still a legitimate use case to pre-render iframe content. That...

Agree that this should be an HTML or CSSWG issue instead.