According to Mercury News, this acquisition is going on for property called "The Landmark at Shoreline" with housing for 960 workers. Google had also confirmed the this acquisition. Google is supposed to be one of the largest buyer of property in the silicon valley.
Come to statics about the Google and it's wide spreading office. Google recently added 2,600 employees in its most-recent quarter, which totals the numbers to 30,000. Also Google had spend around $225M in the year 2011 alone for buying 15 properties in Mountain View. Last year, Google also bought a 2.9 million square-foot office building in New York City.
Source : Mashable