1917729 - Fixed bottom toolbars jerk up and down when the top toolbar shows / hides

Status: RESOLVED DUPLICATE of bug 1797964

(Core :: Panning and Zooming, defect)

Description

[Markus Stange [:mstange]]

Attachment: screen recording

Steps to reproduce:

1. In Firefox for Android, make sure the address bar location is set to Top.
2. Go to any page with a fixed bottom toolbar, such as YouTube.
3. Scroll up and down on the page.

Expected results:

(A) If the new navigation toolbar is disabled: As the dynamic toolbar at the top hides and re-appears, the bottom of the page should remain "calm" - the website's fixed bottom toolbar should remain fixed in place.
(B) If the new navigation toolbar is enabled: The website's bottom toolbar should be moving in sync with the navigation toolbar, with no gaps forming.

Actual results:
(A) The website's bottom toolbar jerks up and down as the dynamic toolbar appears and reappears. You can see part of the website contents in the gap.
(B) The website's bottom toolbar briefly "disconnects" from the navigation toolbar. You can see part of the website contents in the gap.