The ornamental design for a cover of an electronicdevice having surface ornamentation, as shown and described.
FIG. 1 is a perspective view of a cover of an electronic device having surface ornamentation showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a left side elevational view thereof; and,
FIG. 4 is an enlarged fragmentary view thereof showing circled portion 4 in FIG. 2.
In FIGS. 1-3, the evenly segmented broken lines indicate portions of the cover of an electronic device having surface ornamentation that form no part of the claimed design. In FIGS. 2 and 4, the unevenly segmented broken lines indicate the portion of the design that is shown on an enlarged scale in FIG. 4. The broken lines form no part of the claimed design.