From mcasas@:

"Seems like only Samsung Internet cares and didn't respond to my pings before. See this line: https://cs.chromium.org/chromium/src/device/geolocation/geolocation_delegate.h?sq=package:chromium&dr&l=33"

Hopefully we can just get rid of this. If not I'll need to figure out a plan for it, which is nontrivial since it's necessarily a C++ hook to inject a C++ object into the geolocation implementation.