I have a fresh Android 5.1 phone with two separate Google accounts already configured. I just started up the Android Browser and got a confirmation dialog about whether I want to allow Google to use SID and LSID cookies. The popup also referred some kind of Terms and Services document, but wasn't too specific about it. Didn't do anything about it, just went back to the home screen.
On second browser startup, the original confirm dialog was replaced by a popup showing an hourglass animation, and some status message about Google authentication being in progress.
On third browser startup, it just navigated to the factory default homepage.
What exact permissions did the browser / Google request on the first startup? What are the pros/cons for accepting / rejecting access? (I don't really know what a SID/LSID cookies are for, so please be verbose.)
Is there a way to change my mind later on? Where should I look for this configuration option?
Why did the confirmation dialog not show up on the second and third browser startups?