Macro pref

macro_rules! pref {
    ("layout.css.stylo-local-work-queue.in-main-thread") => { ... };
    ("layout.css.stylo-work-unit-size") => { ... };
    ("layout.css.stylo-local-work-queue.in-worker") => { ... };
    ("layout.css.system-ui.enabled") => { ... };
    ("layout.css.basic-shape-rect.enabled") => { ... };
    ("layout.css.basic-shape-xywh.enabled") => { ... };
    ("layout.css.stretch-size-keyword.enabled") => { ... };
    ("layout.css.transition-behavior.enabled") => { ... };
    ($string:literal) => { ... };
}