pub(super) fn add_or_get_font(
layout_context: &LayoutContext<'_>,
font: &FontRef,
ifc_fonts: &mut Vec<FontKeyAndMetrics>,
) -> usizepub(super) fn add_or_get_font(
layout_context: &LayoutContext<'_>,
font: &FontRef,
ifc_fonts: &mut Vec<FontKeyAndMetrics>,
) -> usize