I don't plan to port this add-on to Firefox 57. I'm unaligned with Mozilla's attitude of periodically deprecating their APIs disrespectfully of the maintenance burden they impose on developers, they may receive good PR praising from the users but as an add-on maintainer I've long been fed up.
ATR is made for Firefox so there's no way to use it on Chrome, Opera, Safari or Edge. There are some browsers which partially share the same source code of Firefox and could be compatible with ATR, like Seamonkey and Palemoon, but last time I checked those were lacking features and were not cutting-edge.
The easiest thing is to drop ATR and search for another text-to-speech add-on for Chrome (or Firefox). There are alternatives and some of them have superior features to ATR. Installing such an add-on will give you the highest return for the time spent, as it'd be readily available on the Chrome store, it'd be "guaranteed" to work, and you wouldn't have to write your own scripts in order to have speech synthesis.