Steps to reproduce:
1. Download and open attached project "NavMeshComponents-master.zip"
2. Open Navigation window, so that you could see Navmesh components
3. Play scene and turn on gizmos
4. Try to disable Navmesh surface and renderer gizmos

Actual result: Nothing happens (See: https://gyazo.com/7e9ac95b63afd9766404ca47aee93bda )
Expected: Appropriate gizmos get disabled (Navmesh is not seen anymore)

Tested and reproduced on:
Windows 10
Unity 5.6.0f1

Could not test prior this version, since this is a new feature.