Steps to reproduce:

1. Create new project or download attached one and skip to step 4.
2. Create particle system.
3. Set its render mode to mesh.
4. Look at max/min particle size fields under Rendering module of particle system.

Actual result: They are visible.
Expected result: Since max/min particle size only applies when rendering billboards, it should not be visible when render mode is set to mesh. Causes confusion to users.

Reproduced with: 5.4.0b2, 5.3.1p4, 5.2.4f1