Through Chrome, which was started internally in 2006 and launched externally in 2008. Though that also was one of those projects where Larry sponsored a couple of talented engineers behind Eric's back and they put out something awesome.

Behind Eric's back? A company that has tens of thousands of employees and you think the co-founder would have to hide a small initial implementation of a project he believed in?

Absolutely. If it isn't hidden, the developers will have to deal with management, credit taking, metrics, attempts to squash the project, jealousy from other employees, unreasonable pressure (surely a browser can be written in 3 months ...) and being treated as a cost center.

All this would happen even if backed by Larry.

It is a miracle that new projects happen at all in companies, though Google of course actually bought many successful projects.

There's no way Google had tens of thousands of employees in 2006. Although it was probably large enough (between 5,000 and 10,000) that your point still stands.