A Black line appears on the bottom of the Scene/Game view window while resizing.

Steps to reproduce :
1. Change the scale factor of the screen to 125% / 150% / 175% or more from Window's display settings.
2. Create a new project in Unity.
3. Undock the Scene/Game window.
4. Expand/shrink the window multiples times.

Note: Screenshot is attached for the reference.

Actual Result :
A Black line appears on the bottom of the scene window while resizing.

Expected Result:
All sides of the window has a light blue border, no black line is visible.

Occurring On:
2019.3.0a3

Working fine On:
2019.3.0a2, 2019.2.0b2, 2019.1.0f2

Environment:
Windows Only