Because any HTML element can be focusable by 'tabindex' or 'contenteditable', it should support 'autofocus' as well. Specification PR; https://github.com/whatwg/html/pull/4830 WPT PR; https://github.com/web-platform-tests/wpt/pull/18558
<rdar://problem/54514366>
*** This bug has been marked as a duplicate of bug 203139 ***