It's obviously not a headless browser but xvfb can be very useful depending on what exactly one is trying to test: https://en.wikipedia.org/wiki/Xvfb
Just to throw in another option, there's selenium grid docker containers: https://github.com/SeleniumHQ/docker-selenium. The containers are a bit heavy IMHO (I suppose because they're aimed more at 'testing' instead of scraping), but I think there are a few Alpine Linux versions floating around (and easy enough to set up yourself).
Handy for more tricky sorts of web scraping, or if you want to use chromium in mobile emulation mode (causing websites with an 'app version' to switch over to a HTTP-JSON SPA in many cases). I was particularly excited to discover you can set the 'http_proxy' env variable on a "per-browser node" basis (and do fun stuff like installing DNS caching daemons, round-robinning through OpenVPN/squid containers etc.).