Essentially the damages on copyright are now approaching 'statutory' damages, and not punitive damages or portions of profits from infringement. This was a risk Oracle took when going to a jury trial, and now Judge Alsup will hold them to it.
On the patents side, clearly Google has not knowingly infringed - which would be treble damages. The court has also got expert reports which talk about how much the infringement's upper bound is.
So there is not much for the jury to do in terms of determining the actual damages to be paid out, since on the one hand they are statutory damages, and on the other there are only two patents still in play, and once the jury rules on the patents, the judge can determine the damages.