The entire project is based on Apple's WebKit, which was a cross-platform, arguably best-of-breed browser toolkit on the day they started.
Lars Bak, the architect of V8, has been working on language technologies since the early 90s, including Smalltalk.
A key Chrome team member, Ben Goodger, had already been working on browsers since the Netscape era, and was an early participant in Firefox.
There really are no miracles in software. People used to talk about "Netscape time" or marvel at how Google seemed to come out of nowhere. But even in those cases you can see how prior to those projects becoming household words, they had a long gestation period, during which time they were protected from competition. Netscape included a lot of people from the earlier NCSA Mosaic effort. Google was an academic project that, as an economic entity, grew up in the sheltering shadow of Yahoo.
I'm not saying these people didn't work hard, or aren't brilliant, or don't deserve their success. It's just that whenever you see someone moving much faster than is normally considered possible, don't assume that it's only due to skill. It's far more likely that they had some history of working on the problem, for far longer than you think.