We still need handling for this event. This is fired every time the aria values are updated so when that happens the CSS should be updated as well. Normal HTML5 progress support automatically updates the visuals when the properties change so the same needs to be the case for the polyfill. Suggest restoring the handling (although probably should attach on $document with a selector for the property element). Make sure to turn off the handling while changing CSS (like was done before) to avoid an infinite loop.