Distorted Text appears on the edge of the Objects Packing list in sprite atlas.

Steps to repro:
1. Create a new project.
2. Right-click in Project View > Create > Sprite Atlas.
3. Select newly created Sprite Atlas asset.
4. Expand "Objects for Packing" dropdown.

Actual Result:
Distorted Text appears on the edge of the Objects Packing list.

Expected Result:
No Text appears on the edge of the Objects Packing list.

Reproducible in:
2020.1.0a4, 2019.3.0b4.

Working Fine in:
2020.1.0a3, 2019.3.0b3.

Environment:
Windows & Mac 10.14.