Media: add method to discover whether playback is allowed before calling `play()` · Issue #3617 · whatwg/html

/CC @cpearce @jernoble With autoplay policies, a media element may not be allowed to play depending on various rules: browser setting, user behaviour on the page, etc. It was suggested to expose this as a permission but because the behaviour is often dependant on past user behaviour on the page [1], it may makes sense to expose the information at a media element level. @cpearce suggested canAutopl

[efcl]

自動再生が可能かどうかを判定できる属性について。 playする前に知りたいという話