The ornamental design for a contourgauge, as shown and described.
1. Contour gauge
1.1: Front
1.2: Bottom
1.3: Right
1.4: Top
1.5: Left
1.6: Back
1.7: Perspective
A contour gauge for copying and marking a variety of angles and odd shapes; it creates a template for marking precise cuts to conform to shapes and edges and which holds their pattern with the help of a lock.