The combined mesh data is never getting freed, even though all GameObjects that were used to create the combined mesh have been removed from the scene.

To reproduce:

1. Download attached project "StaticBatchingMemoryLeakTest.zip" and open in Unity
2. Open "TestScene" Scene
3. Enter Play Mode

Expected Result: Memory stays stable
Actual Result: Memory continually increases

Note: You can see as the memory continually increases within the Detailed Memory Profiler: Scene Memory -> Mesh. To see memory usage increase faster, change the "Time Between Creates" on the TestScript GameObject to a lower value. In built players, the memory numbers goes up slower.

Note: This issue appears both on Windows and OSX.

Reproduced on Unity 5.6.2p1, 2017.1.0f1 and 2017.2.0b1
Could not check for regression on Unity 5.5 because scripts becomes corrupted