1825125 - [wpt-sync] Sync PR 39256 - [FLEDGE] Fixup joinAdInterestGroup with a <= 0 duration, add WPT test.

Status: RESOLVED INVALID

(Testing :: web-platform-tests, task, P4)

Description

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Sync web-platform-tests PR 39256 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/39256
Details from upstream follow.

Matt Menke <[e-mail]> wrote:

[FLEDGE] Fixup joinAdInterestGroup with a <= 0 duration, add WPT test.

Previously, we'd calculate the expiration time in the renderer process,
pass that to the browser process, and after permission checks, write
that to the FLEDGE database, even if it were expired. This has a couple
problems:

1. If the system clock went backwards, we'd revive that interest group.
   We're inevitable subject to clock changes in general, but when joining
   an expired interest group, it seems weird to let it come back.
2. Interprocess clock skew. On Windows, at least, the times reported by
   different processes can be slightly different. By calculating expiry
   in one process, but applying it in another, it's theoretically
   possible, if unlikely, that an auction run immediately after join
   could see the "expired" interest group.
3. Even if times are exact, if time exactly equals the expiry, we
   still consider the group valid. Theoretically, the clock could be
   the same between join time and if an auction is immediately run, so
   joining an IG with a duration of 0 and then immediately running an
   auction could return in that IG participating in the auction, with
   no clock skew or clock changes.

Issue 3) Could just be fixed by updating comparisons and updating some
tests, but this CL attempts to fix all these issues. It adds a Mojo
parameter that indicates if the join duration is \<= 0, and if either
that's the case, or the joined interest group is already expired, the
interest group is left rather than being joined. The renderer still
calls the browser's JoinInterestGroup function, so join permissions
are still checked for the calls, since allowing joinAdInterestGroup(x, 0)
but not joinAdInterestGroup(x, 1) due to permissions seems a bit strings.

Bug: 1425952
Change-Id: Ia6796bdd1efe6cea7d749de3961599a3fb99434f
Reviewed-on: https://chromium-review.googlesource.com/4377062
WPT-Export-Revision: bbe8daeac89f15b0607447b4b609f8cd7ab9a9ca