Shaky screens on OS-X

[Clorith]

Due to the what appears to be the OS-X implementation of iOS like features with scrolling past boundaries it seems the admin menu causes screen shaking on pages that involve scrolling.

The issue is restricted to OS-X and does not present it self on Windows

If the cause truly is the boundary overflow scrolling then it might be an issue with generic iOS devices as well like iPads that have a big enough viewport to include the menu by default?

As reported by @sormano in ​https://wordpress.org/support/topic/shaking-screen

[johnbillion]

Confirmed. Reproducible when the admin menu is taller than the browser window.

[azaozz]

In 30692.patch: fix menu "shakiness" in MacOS/Chrome and Safari when over-scrolling. Needs more testing but seems to work better in Chrome than in Safari (Firefox is not affected).

Would be good to get that in 4.1. Alternatively can disable the menu pinning in Chrome and Safari on MacOS.

[azaozz]

In 30844:

Fix menu shakiness when over-scrolling in Chrome and Safari on MacOS.
See #30692.

[azaozz]

In 30852:

Improve the fix for menu shakiness when over-scrolling. Recalculate heights on editor auto-resize.
See #30692.

[nacin]

Are these patches good enough for 4.1? Please remove the keywords I'm adding if not.

[johnbillion]

In 30917:

Fix menu shakiness when over-scrolling in Chrome and Safari on MacOS.

Merges [30844] to the 4.1 branch.

See #30692.

[johnbillion]

In 30918:

Improve the fix for menu shakiness when over-scrolling. Recalculate heights on editor auto-resize.

Merges [30852] to the 4.1 branch.

See #30692.

[johnbillion]

This looks pretty good now.