UI distorts on the override change comparison window for a game object when a changed component is selected. The distortion is more clearly visible for particle system when all the modules are expanded.

Steps to repro:
1. Open the attached or create a new project
2. Hierarchy > right click
3. Effects > particle
4. Darg particle game object in "Project" window to create a prefab
5. Expand all modules of the particle in the "Hierarchy" window
6. Edit any property
7. Click on overrides and drop down and click on the particle system

Actual Result:
1. The UI distorts for a moment on viewing overridden changes

Expected Result:
1. UI should appear seamlessly

Occurring with:
2018.3.0a9 (1671df2d9715) , 2018.3.0a8, 2018.3.0a6

Note:
Improved prefabs were introduced in 2018.3.0a6

Environment:
Occurring only on windows