When Element.focus() is used, the element should be scrolled into view such that the element is in a defined position. Currently dom-focus states:

[...] scroll the element into view with scroll behavior "auto", block flow direction position set to an implementation-defined value, and inline base direction position set to an implementation-defined value.

Added focus/focus-centers-element.html in web-platform-tests/wpt#41029 that essentially checks that Element.focus() behaves similar to Element.scrollIntoView({block: "center", inline: "center"}).

Since browsers seem to agree that Element.focus() should center the element, it might make sense to specify this instead of leaving this implementation defined. Several web-platform tests assume that Element.focus() will cause an element to end in a certain scroll position (e.g. css/css-scroll-snap/scroll-target-margin-005.html), but AFAIK this is essentially undefined behavior (at least from the specs point of view).