StyleProperties::getPropertyValue() has a big switch like this:

    switch (propertyID) {
    case CSSPropertyAll:
        return getCommonValue(allShorthand());
    case CSSPropertyAnimation:
        return getLayeredShorthandValue(animationShorthand());
    case CSSPropertyBorderSpacing:
        return borderSpacingValue(borderSpacingShorthand());
    case CSSPropertyBackgroundPosition:
        return getLayeredShorthandValue(backgroundPositionShorthand());
    case CSSPropertyBackground:
        return getLayeredShorthandValue(backgroundShorthand());
    ...

Most shorthands need to get the StylePropertyShorthand using allShorthand(), animationShorthand(), ...

But before the switch it calls commonShorthandChecks(), which uses shorthandForProperty(propertyID) to get the StylePropertyShorthand.

So this StylePropertyShorthand can be reused.