The ornamental design for a cover of an electronicdevice with surface pattern, as shown and described.
FIG. 1 is a perspective view of a cover of an electronic device with surface pattern showing our new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a 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 with surface pattern that form no part of the claimed design. In FIGS. 2 and 4, the unevenly segmented broken lines indicate the portion of the cover of an electronic device with surface pattern that is shown on an enlarged scale in FIG. 4. The broken lines form no part of the claimed design.