Founded some mesh wireframe shader in the unity 5.5f2 builtin shader folder (builtin_shaders-5.5.0f2\DefaultResourcesExtra\VR\Shaders)..
Changes:
– Added fillcolor, outline color
– Added [x] Discard option (draws only lines)
– Removed stereo rendering keywords
– Removed color by distance thing
Download shader:
https://github.com/UnityCommunity/UnityLibrary/blob/master/Shaders/Effects/WireFrame.shader
Tip: You can assign this material shader as a 2nd material to your mesh, to draw original material + wireframe (with [x] discard enabled)