1. Passive event listeners

    Event listeners created with the `passive: true` option cannot cancel (`preventDefault()`) the events they receive. Primarily intended to be used with touch events and `wheel` events. Since they cannot prevent scrolls, passive event listeners allow the browser to perform optimizations that result in smoother scrolling.

  2. eventtarget api: addeventlistener: form with `options` object supported (third parameter can be either options or a `boolean`, for backwards compatibility): `passive` option

  3. eventtarget api: addeventlistener: form with `options` object supported (third parameter can be either options or a `boolean`, for backwards compatibility): `passive` option defaults to `true` for `touchstart` and `touchmove` events

  4. eventtarget api: addeventlistener: form with `options` object supported (third parameter can be either options or a `boolean`, for backwards compatibility): `passive` option defaults to `true` for `wheel` and `mousewheel` events