I'm pretty sure Google Chrome has an API hidden away for payment info. Google seems to market it towards ecommerce developers (that's how I found out about it), but I can't find my documentation on it. Plus it's not on track for any sort of standardisations.

Do you mean https://developers.google.com/web/fundamentals/input/form/us... ?

If so, it has since become standards track: https://html.spec.whatwg.org/multipage/forms.html#dom-form-r...