Viewport-related tests

[bramus]

There’s a bunch of suggested tests specifically targeted towards mobile devices that came out of the Viewport Investigation from Interop 2022: web-platform-tests/interop-2022-viewport#23 (comment). It would be nice if these could be possible as the outcome of this effort (Also see: #1)

During the Viewport Investigation we also did the exercise of listing which internal APIs would be needed to allow these tests: web-platform-tests/interop-2022-viewport#23 (comment).

I hope this information is useful – or could form a starting point – for future discussions part of this Mobile Testing Investigation.