Chrome Wayland Scaling Issue
Definitely (and unfortunately) not realted to Chrome only - it doesn't work in any app running via XWayland currently.
See Wayland: Multi DPI Setup for nice explanation and current state (as of Sep 2018):
...Because (these) apps don't fully support Wayland yet, they still use the X11 protocol with XWayland, which doesn't handle MultiDPI well (GNOME has ideas, but I doubt whether this will happen).