I claim the ornamental design for an apron, as shown and described.
FIG. 1 is a back elevation view of an apron.
FIG. 2 is a front elevation view thereof.
FIG. 3 is a front elevation view thereof, wherein the apron is in a configuration of use.
FIG. 4 is a back elevation view thereof.
FIG. 5 is a left-side elevation view thereof.
FIG. 6 is a right-side elevation view thereof.
FIG. 7 is a top plan view thereof.
FIG. 8 is a bottom plan view thereof.
FIG. 9 is back perspective view thereof; and,
FIG. 10 is a partial back view thereof.
The portions of the apron illustrated in uneven broken lines and the surfaces immediately adjacent to the uneven broken lines that do not contain shading form no part of the claimed design. Any evenly broken lines in the drawings illustrate stitching portions of the apron that form part of the claimed design.