An ornamentaldesign for an adapter with ball mount for supporting an electronicdevice, as shown and described.
FIG. 1 is a front, top, left perspective view of an adapter with ball mount for supporting an electronic device;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a right side elevation view thereof;
FIG. 5 is a left side elevation view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines shown in FIG. 7 illustrate portions of the adapter with ball mount for supporting an electronic device that form no part of the claimed design.