1725018 - [wpt-sync] Sync PR 29977 - Revert "Make classlist update for XML namespace nodes"

Status: RESOLVED FIXED

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

Description

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

Sync web-platform-tests PR 29977 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/29977
Details from upstream follow.

b'Mason Freed <[e-mail]>' wrote:

Revert "Make classlist update for XML namespace nodes"

This reverts commit 5e25e22bb1642b26bc87e097ca00f54dd6ed8b88.

Reason for revert: Many perf regressions:

https://bugs.chromium.org/p/chromium/issues/list?q=id%3A1238218%2C1238219%2C1238224%2C1238235%2C1238239%2C1238244%2C1238245%2C1238247%2C1238285&can=2

Original change's description:

Make classlist update for XML namespace nodes

Prior to this CL, CSS selectors like .classname would not match
XML namespace elements that had a class attribute with a value
of classname. However, *[class~="classname"] would match those
elements, querySelectorAll() would also match, and (perhaps most
importantly), Gecko, Webkit, and the spec all indicated that these
elements should be matched:

https://dom.spec.whatwg.org/#dom-element-classname

This could cause a minor perf regression, since ElementRareData will
be attached in more cases (memory regression), and the early-outs
in UpdateClassList have been removed (speed regression). I am
hopeful that these should be minor for ordinary HTML usage, but
we'll see.

Fixed: 649444
Change-Id: Ic846722830d76df801d2a8e33c360bfa41822cf6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3077706
Commit-Queue: Mason Freed \<[e-mail]>
Auto-Submit: Mason Freed \<[e-mail]>
Reviewed-by: Rune Lillesveen \<[e-mail]>
Cr-Commit-Position: refs/heads/master@{#910038}

Change-Id: Ie5cb1955adf7638d11d1a850d4a6201384141ea6
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3086222
Bot-Commit: Rubber Stamper \<[e-mail]>
Commit-Queue: Mason Freed \<[e-mail]>
Cr-Commit-Position: refs/heads/master@{#910450}

Comment 1

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

PR 29977 applied with additional changes from upstream: a536835a5e3ee67cf0ec0660f42649d395b33d2a

Comment 2

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

Pushed to try https://treeherder.mozilla.org/#/jobs?repo=try&revision=420fb0b95106e5c46c017001d5b9e272a6b40af9

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/949e0f5113f1
[wpt PR 29977] - Revert "Make classlist update for XML namespace nodes", a=testonly

Comment 4

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

Test result changes from PR not available.

Comment 5

[Iulian Moraru]

https://hg.mozilla.org/mozilla-central/rev/949e0f5113f1