Steps to repro:

1. Open Unity;
2. Create new project and scene;
3. Open Profiler window;
4. Click 'Profile Editor' to enable editor profiling;
5. Select 'Memory' tab;
6. Observe 'Meshes', 'Total Objects in Scene' and total used memory fields;

Actual result:
Number of meshes and total used memory is steadily increasing, creating a memory leak (see attached gif video). Reproduces only when focused on Profiler window.

Expected result:
Number of meshes should not steadily increase after enabling 'Profile Editor' feature.

Notes:
- Reproducible in: 5.5.0a1, 5.4.0b11, 5.4.0b10, 5.3.4f1, 5.3.3f1, 5.2.2p4;
- Reproducible on both OSX 10.11.3 and Windows 10;
- Removing focus from Profiler windows releases memory, though the number of meshes still continues to increase.