Google Fonts, Google Public DNS, Google Analytics, Google+ like gadgets, Google Adsense, Google CDN for jQuery etc, Google services like Search and Gmail, Embed

Google Fonts, Google Public DNS, Google Analytics, Google+ like gadgets, Google Adsense, Google CDN for jQuery etc, Google services like Search and Gmail, Embedded Youtube videos, Google Chrome word correction sugesstions and safe sites checks, Firefox safe page checks, probably many things within Android backend. Probably they know with 99.9999999% accuracy how many online web users are out there.