They interviewed me :P (no, didn't get the job), My GPA was about 2.8 at the time. Also, if Google has a mark cutoff, it is not made public (suggesting that there are circumstances where they will ignore a low grade).
NVidia on the other hand made their intentions very clear, and basically said to not bother if your GPA was below 3.5, right in the job description.
Isn't Google notorious for requiring a 3.0 or better GPA?