1765347 - Audit and possibly simplify IPC of 3rdPartyStorage permission usage

Status: ASSIGNED

(Core :: Privacy: Anti-Tracking, enhancement, P3)

Description

[Benjamin VanderSloot [:bvandersloot]]

I want to be certain:

• no IPC is performed where it does not need to happen
• all IPC is happening using uniform conventions (mozPromise is nice)
• invariants of IPC are clearly documented.

Comment 1

[Martin Raiber]

Attachment: Bug 1765347 - Part 1 - Ask whether storage access can be granted automatically together with the permission lookup r?#anti-tracking!

requestStorageAccess() from a third party that isn't a tracker asked the
parent for the existing permission, and then in a second round trip
whether access can be granted without a prompt.

Optimize this by asking the parent for both pieces of information in a
single round trip.

Comment 2

[Martin Raiber]

Attachment: Bug 1765347 - Part 2 - Mark FedCM continuation windows with a browsing context field. r?#anti-tracking!

The popup heuristic asked the parent on every first interaction in a third-party
popup whether it is a FedCM continuation window, which must not get storage
access. The parent now sets a field on the window instead, which the heuristic
reads without IPC.