Apparently it switched to Webkit a while back.
Why does this keep happening? Browsers sell their soul to just be another coat of paint on top of WebKit. I honestly don't get it. If you're working on a web browser as a personal or open source project, switching to WebKit is basically just replacing the entire project that you've worked on, and then writing your name on WebKit. There's not much more to a browser than a rendering engine. There really isn't a killer…
Things outside the web rendering engine also prevent more widespread adoption of alternative browsers as well. Google's WildVine DRM is an example. That doesn't ship with chromium.