Computes the logical and ink extents of @layout_line in device units.
This function just calls pango_layout_line_get_extents() followed by
two pango_extents_to_pixels() calls, rounding @ink_rect and @logical_rect
such that the rounded rectangles fully contain the unrounded one (that is,
passes them as first argument to pango_extents_to_pixels()).
Computes the logical and ink extents of @layout_line in device units. This function just calls pango_layout_line_get_extents() followed by two pango_extents_to_pixels() calls, rounding @ink_rect and @logical_rect such that the rounded rectangles fully contain the unrounded one (that is, passes them as first argument to pango_extents_to_pixels()).