According to Unity Documentation (https://docs.unity3d.com/ScriptReference/MeshTopology.Quads.html), MeshTopology.Quads should generate a draw call that uses 4 point patches, however, it uses a 3 point patches instead.

Steps:
1. Open user's attached project "New Unity Project (3).zip"
2. Open Assets/Sccenes/SampleScene and enter Play mode
3. Record a frame using RenderDoc
4. In RenderDoc, in EventBrowser, select Camera.Render/DrawIndexed()
5. In API Inspector. select ID3D11DeviceContext::IASetPrimativeTopology/Topology

Expected: 4 point patch is used (D3D_PRIMITIVE_TOPOLOGY_4_CONTROL_POINT_PATCHLIST)
Actual: 3 point patch is used (D3D_PRIMITIVE_TOPOLOGY_3_CONTROL_POINT_PATCHLIST)

Reproduced with: 2018.1.9f2, 2018.2.8f1, 2018.3.0b2, 2019.1.0a1
Not reproduced with: 2017.4.11f1