v8 wasn't developed by a separate company, but Bak did bring at least one of his colleagues along to Google (I'm pretty sure just as new employees to Google). And he had another company that worked on a SmallTalk VM called OOVM, targeted at embedded devices, right before he joined Google:

https://astares.blogspot.com/2012/04/inside-oovm.html

However it apparently wasn't acquired by Google:

http://www.businesswire.com/news/home/20040727005088/en/Esme...

Other discussion:

http://forum.world.st/OOVM-details-td4561492.html