The ornamental design for a giftwrappingbag, as shown and described.
FIG. 1 is a perspective view of the gift wrapping bag of the present invention;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a top view thereof;
FIG. 5 is a bottom view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is left side view thereof;
FIG. 8 is an environmental perspective view thereof, illustrating a gift inserted into the gift wrapping bag; and,
FIG. 9 is an environmental perspective view thereof, illustrating a gift inserted into the gift wrapping bag and the top of the bag in a closed position.
The portions of the gift wrapping bag illustrated in broken lines form no part of the claimed subject matter.