Block 3rd party tracker cookies

[vesta0]

Why/User Benefit/User Problem

As a user I want to also have the option of only blocking the 3rd party tracker cookies so I can have a good browsing experience and still have some cookie protection.

What / Requirements

This cookie capability is being shipping as part of Firefox 63 and I believe it is GV dependent.

[cpeterso]

GV bug to add API for blocking third-party tracker cookies: https://bugzilla.mozilla.org/show_bug.cgi?id=1495030

TBD whether GV 63 has the tracker cookie blocklist that this feature needs. GV 63 will ship on October 23. GV 64 won't ship until December 12, after Focus 8.0 will ship.

[vesta0]

Desktop team indicated that In Fx 65 desktop, the way they are blocking third party tracker cookies is
through the new storage access policy based on definitions in the Disconnect lists. This feature will block opaque third-party trackers on the Disconnect lists from storing data such as cookies and thus engaging in cross-site tracking. Considering that in Focus we have the Disconnect lists enabled by default, this will not add much value in the short term - but it could in the longer term when the API includes blocking cookies from unvisited sites, etc.

[ekager]

I added the option for GV to block 3rd party tracker cookies with our current menu UX in #3749, leaving this bug open for the new UX.

[vesta0]

Thanks @ekager! I think you can close this because the new UX and strings is also tracked here: #2452