I claim the ornamental design for a hood for a barbecue grill, as shown and described.
FIG. 1 is a perspective view of a hood for a barbecue grill, showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is a perspective view thereof, the portions of the barbecue grill shown in broken lines is for illustrative purposes only and forms no part of the claimed design.