Elements which are transitioning to display:none should be inert.
Asserts run
Pass
assert_not_equals(Element node <body><dialog class="ready"> <button>button</button> </..., Element node <button>button</button>, "Inert elements should not be focusable.")
at Test.<anonymous> ( /css/css-transitions/inert-while-transitioning-to-display-none.html:30:3)