To reproduce:
1. Open attached Unity project "CameraDepth"
2. Open Test scene
3. Go into play mode

Expected result: "Camera Red Depth 2" should overlap the blue camera when it is called since its depth is higher.
Actual result: "Camera Red Depth 2" renders behind the blue camera despite that its depth is higher.

Regression first introduced in 5.6.0a1
Reproduced on 5.6.0a1, 5.6.0f1, 5.6.0f3, 5.6.0p4, 2017.1.0b3
Not reproduced on any version of 5.5

Note: Added gifs "expected.gif" which was made in 5.5.3p2 and "actual.gif" which was made in 5.6.0p4