Bug 1734907 [wpt PR 31166] - [GridNG] Fix auto-placement with items spanning multiple...

Bug 1734907 [wpt PR 31166] - [GridNG] Fix auto-placement with items spanning multiple rows (again), a=testonly

Automatic update from web-platform-tests
[GridNG] Fix auto-placement with items spanning multiple rows (again)

Fixing an issue in the auto-placement algorithm where, if the current
position moved past the `EndOnPreviousMajorLine` of an overlapping item,
when calling `MoveToNextMajorLine` the major end line of such item would
not be taken into account because it will be removed from the vector by
the time its called. A similar issue was fixed previously, but at the
time were items are introduced to the overlapping item's heap.

Running a perf job showed that, as expected, no performance regression
is introduced since this CL only changes some conditionals performed at
the time of inserting/deleting any overlapping item.

A new test to cover the regression was also added to the WPT suite.

Bug: 1255298
Change-Id: Id5a5db3e0b999832767cd512794c5eebdff17286
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3213920
Commit-Queue: Ethan Jimenez <ethavar@microsoft.com>
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Reviewed-by: Ana Sollano Kim <ansollan@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#930306}

--

wpt-commits: 44642faf7d0f2156084c4d0689343786002bcb1c
wpt-pr: 31166