W3C Spec for overflow
This tweak to Google Chrome for Android seems to be directed by the W3C spec for overflow and it’s use. Overflow-x or overflow-y seem to be becoming redundant, whether overflow is x or y it seems they will be treated as one entity, most likely being deprecated at some point.
Overflow on a body tag will take the viewport size and apply it. This might not be expected behaviour for some front end devs.