[CSS Cascade Layers] Unflake and fix web-platform-tests/css/css-cascade/layer-statement-before-import.html

[Antti Koivisto]

Newly imported 

imported/w3c/web-platform-tests/css/css-cascade/layer-statement-before-import.html

is flaky.

[Antti Koivisto]

Created attachment 446987 [details]
Patch

[Antti Koivisto]

Submitted web-platform-tests pull request: https://github.com/web-platform-tests/wpt/pull/32029

[EWS Watchlist]

This patch modifies the imported WPT tests. Please ensure that any changes on the tests (not coming from a WPT import) are exported to WPT. Please see https://trac.webkit.org/wiki/WPTExportProcess

[Tim Nguyen (:ntim)]

Comment on attachment 446987 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=446987&action=review

> LayoutTests/imported/w3c/web-platform-tests/css/css-cascade/layer-statement-before-import.html:170
> +      await new Promise(resolve => {
> +        styleElement.onload = resolve;
> +        styleElement.onerror = resolve;

Shouldn't we reject on error?

```
await new Promise((resolve, reject) => {
  styleElement.onload = resolve;
  styleElement.onerror = reject;
});
```

or alternatively:

```
await new Promise(resolve => {
  styleElement.onload = resolve;
  styleElement.onerror = t.unreached_func("Style element should load");
});
```

[Antti Koivisto]

doesn't really matter for this test?

[Simon Fraser (smfr)]

Comment on attachment 446987 [details]
Patch

r+ but address Tim's test issue if appropriate.

[EWS]

Committed r286949 (245174@main): <https://commits.webkit.org/245174@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 446987 [details].

[Radar WebKit Bug Importer]

<rdar://problem/86414213>