Fix inspector/css test assertions after r253158

[Simon Fraser (smfr)]

Fix inspector/css test assertions after r253158

[Simon Fraser (smfr)]

Created attachment 384967 [details]
Patch

[EWS Watchlist]

This patch modifies the inspector protocol. Please ensure that any frontend changes appropriately use feature checks for new protocol features.

[Devin Rousso]

Comment on attachment 384967 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=384967&action=review

r=me, with one additional fix

> Source/WebCore/ChangeLog:8
> +        No new tests (OOPS!).

Oops.

> Source/WebInspectorUI/UserInterface/Controllers/CSSManager.js:754
> +    Highlight: "highlight",

In addition to this, I think the only thing that's necessary for the Web Inspector frontend to handle this is adding the following to `WI.CSSManager.displayNameForPseudoId`:
```
    case CSSManager.PseudoSelectorNames.Highlight:
        return WI.unlocalizedString("::highlight");
```
Without this, the Web Inspector frontend would log an error to the console.  I'd rather fix both the backend `ASSERT` and any frontend requirements at the same time.

It's not necessary to add it to the switch-case inside the `if (!InspectorBackend.Enum.CSS.PseudoId)` as that's only used for compatibility purposes when inspecting older webpages, meaning that path won't be taken when inspecting a page that has `PseudoId::Highlight` defined.

[Simon Fraser (smfr)]

https://trac.webkit.org/changeset/253176/webkit

[Radar WebKit Bug Importer]

<rdar://problem/57679991>