If you are being considered by Google and are negotiating financial terms I would venture that you have plenty of other options available to you (read Facebook and MS)
If you're being considered by Google and you don't negotiate, perhaps they are the ones making the mistake.
Btw., that's pretty much what happened at my current workplace: after two years of employment I negotiating salary increase -- basing on market situation and possible other employers for me -- and ever since the owners appreciate my role in the company more.