Chrome Version: 71.0.354.0

What steps will reproduce the problem?
(1) Enable auto hide shelf
(2) show shelf by moving the mouse nearby. This does not repro when swiping to show the shelf.

What is the expected result?
Blur is shown at all times

What happens instead?
Blur doesn't show until the shelf is at its final position, unlike showing the shelf with a swipe.
https://photos.app.goo.gl/1LL3J3WXwV8cXFY69


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