As of version 66 of Google Chrome onwards it will no longer automatically start playback of audio and video files when the playback volume is not muted.
This change
It turns out that the end user will have to enable automatic video playback manually, by:
chrome://flags/#autoplay-policy
From now on autoplay works again in webview components used in your app.
See this comment thread about this topic by Google.
This function is often useful on kiosks, where you want to autoplay sound from one specified site. In that case, you can just to to:
And enable autoplay for particular website. It should override its default behaviour and play the sound immediately after displaying site.