Google can't build products, they didn't build anything useful since Search and Docs, so they won't be able to compete. Add a couple of years for consumers to catch on and migrate.

So I would give it 5-7 years in which the employees will slowly be demotivated by waves of layoffs, morale will tank, and accelerate the process. In that time, the upper mgmt will scramble to increase their bonuses to get as much as they can out of the sinking ship. In the end the company will face restructuring and be left with maybe 10% of the current size, trending downward.