Chrome Version: 67.0.3372.0
OS: ChromeOS

What steps will reproduce the problem?
(1) Maximize any app (Chrome or Files)
(2) Swipe from the bottom of the screen
(3) Observe the shelf to slide up
(4) Swipe the shelf down
(5) Observe the shelf to slide down

What is the expected result?
The shelf slides up an down smoothly and has consistent look.

What happens instead?
While begin dragged up, the shelf background is gray, and turns black only when the drag is complete
While being dragged down, the shelf "resists" dragging and it takes a few attempts to finally get it to slide down. Once the drag is complete, the resizing of the maximized window looks quite janky.