Bug 1839141 [wpt PR 40616] - [css-nesting] Support nested layer rules…

…, a=testonly

Automatic update from web-platform-tests
[css-nesting] Support nested layer rules

This CL adds support for nested layer rules, using the same boilerplate
we use for other rules (media, etc).

This was not part of the initial release of css-nesting, because it was
added to the specification too late in the process. However, the intent
of the spec is to allow nesting of all at-rules that contain style rules
in their body [1].

Renamed AllowedRulesType::kConditionalGroupRules to kNestedGroupRules,
since it's not just conditional rules that are allowed to nest anymore.

[1] https://drafts.csswg.org/css-nesting/#nested-group-rules

Fixed: 1455887
Bug: 1451088
Change-Id: I76a9463442bec3e7e6425ddc851ddbf14690604b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4624568
Reviewed-by: Steinar H Gunderson <sessechromium.org>
Commit-Queue: Anders Hartvoll Ruud <andruudchromium.org>
Cr-Commit-Position: refs/heads/main{#1160192}

--

wpt-commits: ac7d2531184610cced5432fdcfdf2564ab54f053
wpt-pr: 40616

UltraBlame original commit: 5c64c9dbf0a130ad4d691b76672df783b0a9abc4

testing/web-platform/tests/css/css-nesting/nesting-layer.html

@@ -0,0 +1,335 @@
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