Add "slotted" to PseudoElement map now that new CSSParser is enabled

[Joseph Pecoraro]

From CSSParserValues.cpp:

>    if (pseudoType == CSSSelector::PseudoElementUnknown) {
>        // FIXME-NEWPARSER: We can't add "slotted" to the map without breaking the old
>        // parser, so this hack ensures the new parser still recognizes it. When the new
>        // parser turns on, we can add "slotted" to the map and remove this code.
>        if (pseudoTypeString.startsWithIgnoringASCIICase("slotted"))
>            pseudoType = CSSSelector::PseudoElementSlotted;
>        else
>            return nullptr;
>    }

Looks like slotted can now be added to the map.

I assume it means:
Source/WebCore/css/SelectorPseudoClassAndCompatibilityElementMap.in

[Anne van Kesteren]

Source/WebCore/css/SelectorPseudoElementMap.in and that has happened now.