1387760 - scroll tab-bar using < > arrows jerks & is slow

Status: RESOLVED DUPLICATE of bug 1387130

(Firefox :: Untriaged, defect)

Description

[Bill his name]

User Agent: Mozilla/5.0 (Windows NT 10.0; rv:57.0) Gecko/20100101 Firefox/57.0
Build ID: 20170805100334

Steps to reproduce:

Browse 
using Nightly 57.0a1 (2017-08-05) (32-bit) under windows10

Get several tabs (more than tab-bar horizontal allocation).

Use < > arrows at sides of tab list to scroll tabs (left or right)


Actual results:

Slowly, slowly, & jerkily
the tab-bar moves in tab-sized increments.
I  estimate  the  rate  to  be  700ms  per  tab

This  languid  sluggishness  interrupts  work flow.

Using mouse-wheel to scroll tabs remains acceptable smooth scroll. 

~~~~
Additionally, when horizontal scrolling inside a rendered page using keyboard arrows,
there is similar slow jerky behaviour.

~~~~
UX - Also, it is difficult to regain focus to current tab if tab is scrolled out of view.


Expected results:

When using < > arrows, tabs should scroll nicely at a usable rate.

Not too slow, not too fast, just right for everybody. Regardless of reaction times or impatience quotient.

Whether smooth or in tab-sized increments is a matter of personal preference for Users. 
IMO, the jerks do have potential for increasing precision.

{Where can one see, discuss & influence style points?}

~~~~
.. so should web-pages scrolll politely when using keyboard arrow. No jerks. 

~~~~
Adjunct: it should be easy to regain focus on current tab when it has moved.
Because one may need tab drop-down buttons.