It was bound to happen eventually. Big projects like Chromium tend to move slowly so it will probably be a few years before any Rust code ends up in a shipped release. But this is a great start!
In fact there are articles of people burning out with the release process of Chrome, left behind by the sheer speed at which the project is moving forward.
[1] https://chromium.googlesource.com/chromium/src/+/HEAD/styleg...