The documentation on this can be found in the main README.md.
There is no explicit versioning being done. At the time of writing no compelling use case was found that would require version numbers. Commits are identified by their commit hash, which should suffice for the projected future.
For each Chromium release branch, we create a mirror branch with the same name on our repo. Rough outline:
Generally speaking, beta/stable branches are the same as Canary branches. There is a special waterfall though, that runs tests on the beta/stable branches.
Todo: mention what needs to be done when Chromium updates to a new major version
The Skia autoroller is used. The DevTools-Frontend auto-roller state can be seen and controlled here.