Google has a lot of areas where they could bring in growth.
Google Glass - Could be as big as the iphone was
Computer driven cars - seems unlikely this will happen anytime soon or ever, but it's possible I guess.
Google+ - I haven't looked on there to see if it is any more active, but they could possibly start competing with FB similar to how Android competed with Apple. I like Google+ like 10x more than FB, but nobody seems to use it.
Oh and they have chrome, gmail, drive, fiber, youtube, and nobody can touch them in search. All of those are going to grow as more and more people use the internet more and more often.