I don't know why this keeps coming up. It would violate their privacy policy to do anything like that, they've said they're not going to do anything like that, and if they did do something like that it would be easily detected and there would be a massive, unrecoverable backlash.
If you want to play conspiracy theory, why don't you ponder what percentage of sites have Google Analytics or +1 javascript installed?
I think you've misread the parent. nupark2 is distinguishing between what Amazon is planning and what Google do. jcampbell is saying "doesn't this already exist" and nupark2 is saying no.
Like the "unrecoverable backlash" they suffered for the App Engine pricing scandal, the net neutrality scandal, "If you have something to hide..." and their making a big stink about pulling out of China and then not actually doing it until China started hacking their servers?
Google could do anything they wanted, no matter how evil and there will still be an endless steam of fanboys defending them.
... and if instead, Google built reporting of visited sites and all their contents, cookies, and your personal information into Chrome?