subpixels: radiusX and radiusY affected by retina display in synthesized touch events
Touch Events on macOS indirectly leak user's screen DPI.
Original discussion: legacy/trac#10286 (moved) Upstream: https://bugzilla.mozilla.org/show_bug.cgi?id=1364969
There has not been any traction upstream for quite awhile, so we should consider fixing this ourselve and upstreaming.