No Google forked Webkit into Blink[1] about two years ago.

[1] http://www.chromium.org/blink

Chrome no longer uses Webkit; it uses a fork called Blink. (Technically a fork of WebCore, the core of WebKit.) It's similar, but has diverged since the fork.

Not really anymore. Google forked part of WebKit to create Blink[1], and both Safari and Chrome have their own optimizations.

I'm not sure how close to each other these rendering engines are. I imagine they're still very very similar, but now that the fork has occurred, time will tell how divergent (or not) they become.

[1] http://en.wikipedia.org/wiki/Blink_(layout_engine)

They actually forked WebKit and use Blink now, but they obviously still share a lot of the same code as the fork is relatively recent.

https://en.wikipedia.org/wiki/Blink_%28layout_engine%29

Even when they were using WebKit, it was never the same version, and they had patches. So there never was a unique WebKit rendering engine.

They forked webkit, actually, and use something called Blink.

Check this out for a good summary: https://www.youtube.com/watch?v=dQw4w9WgXcQ