visibilitychange: add note for Safari bug with window.addEventListener (#7335)
visibilitychange: add note for Safari bug with window.addEventListener (#7335)

Source: https://github.com/w3c/page-visibility/issues/68#issuecomment-724981272
chrisdavidmills/browser-compat-data,chrisdavidmills/browser-compat-data,mdn/browser-compat-data,mdn/browser-compat-data