Tab does not always gets revealed when activating it via keyboard

[alexdima]

Findings: the tabs widget currently does not detect when the underlying div scrolls. Need to listen for scrolling (e.g. caused by going through elements with tab and focussing them) and update the custom scrollbar accordingly.

Testing #7854

• a lot of ctrl+m to get all editors move focus
• shift-tab to reach the tab
• space to select the tab
• doing it with the mouse seems to always reveal it

[bpasero]

Weird, works for me on Mac at least.

[bpasero]

For me it even reveals the tab while I am tabbing through.

[alexdima]

Sometimes it works, but maybe after clicking on them or selecting a few it stops working. I will try to see if I find what brings it in this state...

[bpasero]

Thanks!