Function align_inline_boxes 

pub fn align_inline_boxes(
    lines: &mut [InlineVisualLine],
    boxes: &mut [PositionedInlineBox],
    size: &mut Size<Pixels>,
    requests: &[InlineBoxRequest],
    line_metrics: &[InlineTextMetrics],
    text_bounds: &[(Pixels, Pixels)],
    fallback_metrics: InlineTextMetrics,
    line_height: Pixels,
)

Applies CSS-like vertical alignment to boxes after a text backend assigns them to lines.