'use strict'; /** * Returns a Promise that is resolved after a CSS scroll timeline is created (as * the result of a style change) and a snapshot has been taken, so that the * animation style is correctly reflected by getComputedStyle(). * Technically, this only takes a full frame update. We implement this as two * requestAnimationFrame callbacks because the result will be available at the * beginning of the second frame. */ async function waitForCSSScrollTimelineStyle() { await waitForNextFrame(); await waitForNextFrame(); } function assert_implements_animation_timeline() { assert_implements(CSS.supports('animation-timeline:--foo'), 'animation-timeline not supported'); }