[LayoutNG] Fix `vertical-align: top` and `bottom`

[chromium-wpt-export-bot]

This patch fixes vertical-align: top and bottom when
they are applied to a box that has children with text-top
or text-bottom.

In LayoutNG, vertical-align is handled in 3 different
timings.

1. top and bottom are added to the pending list of the
   line box, or to the nearest ancestor box that has top or
   bottom.
2. text-bop and text-bottom are added to the pending list
   of the parent box.
3. Other values are computed when the box is closed.

When a box has both 1 and 2, this patch changes to compute 1
(top and bottom) after 2. Before this patch, both 1 and 2
are computed at the same time for each box. 3 test cases out
of 20 in this test fails without this patch.

Bug: 1001664
Change-Id: I0e7746447f5e401837c2c28e308171f0987eba35
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1792396
Reviewed-by: Emil A Eklund <eae@chromium.org>
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#695194}

[wpt-pr-bot]

Already reviewed downstream.

[foolip]

I came here to check on the Taskcluster failure, which is because of the test being flaky in Chrome Dev. But it looks like something has also gone quite wrong here, the PR doesn't match https://chromium.googlesource.com/chromium/src/+/cf88186a260efa4875553eb99f79bbbff8d3130a.

I'll comment on the difference. @Hexcles can you take a look at how this happened?

[foolip]

Oh, wait, @LukeZielinski pushed a commit that accounts for the difference. Just need to make sure the fix works then.

[foolip]

Changes make sense, and https://wpt.fyi/results/css/CSS2/linebox/vertical-align-top-bottom-001.html?label=pr_head&max-count=1&pr=18956 results look good.