History:

• my first bug 1579631
• duplicated to bug 1504787 and about:config solution
• regression after layout.css.scrollbar-color.enabled was removed by bug 1641324
• userContent.css solution bug 1645676

[rdk@on ~]$ mozregression --good  2021-01-28 -p /media/on/doc/tmplc9zis4t.mozrunner/ --pref security.sandbox.content.level:0 ^C
...

12:35.66 INFO: Downloading build from: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/bdhjyENSSyixx_ft42Ewfw/runs/0/artifacts/public%2Fbuild%2Ftarget.tar.bz2
===== Downloaded 100% =====
13:24.27 INFO: Running autoland build built on 2021-02-03 11:59:17.781000, revision d6481478
13:37.20 INFO: Launching /tmp/tmp_ehuocfz/firefox/firefox
13:37.20 INFO: Application command: /tmp/tmp_ehuocfz/firefox/firefox --allow-downgrade -profile /tmp/tmp4nmg7yyo
13:37.21 INFO: application_buildid: 20210130161107
13:37.21 INFO: application_changeset: d6481478a8e01366fb3af2e0788aa6666429d5f1
13:37.21 INFO: application_name: Firefox
13:37.21 INFO: application_repository: https://hg.mozilla.org/integration/autoland
13:37.21 INFO: application_version: 87.0a1
Was this integration build good, bad, or broken? (type 'good', 'bad', 'skip', 'retry', 'back' or 'exit' and press Enter): good
13:46.72 INFO: Narrowed integration regression window from [a3231eeb, d9e5a018] (3 builds) to [d6481478, d9e5a018] (2 builds) (~1 steps left)
13:46.73 INFO: No more integration revisions, bisection finished.
13:46.73 INFO: Last good revision: d6481478a8e01366fb3af2e0788aa6666429d5f1
13:46.73 INFO: First bad revision: d9e5a018312eccf63acbda32759d90e2f92175d7
13:46.73 INFO: Pushlog:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=d6481478a8e01366fb3af2e0788aa6666429d5f1&tochange=d9e5a018312eccf63acbda32759d90e2f92175d7

This is just a very minor perf optimization which skips generating some
elements.

They look ok as-is, but make it an opt-in for now.

Backed out changeset edb53b07e9c0 (Bug 1690812) for causing reftest failures in xul-scrollbar-iterate.html CLOSED TREE

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&group_state=expanded&collapsedPushes=842382&resultStatus=testfailed%2Cbusted%2Cexception%2Cretry%2Cusercancel&revision=edb53b07e9c063a3a1c38e0b9b541a6644f5b3a1&selectedTaskRun=dQ0R9wVaRkKNlAw7HqJslQ.0

Failure log: https://treeherder.mozilla.org/logviewer?job_id=328884381&repo=autoland&lineNumber=15233

Backout: https://hg.mozilla.org/integration/autoland/rev/1619817947120d56d1bcc97d9a57e4e272a0fa28

I'll move the second patch to some other bug.

https://hg.mozilla.org/mozilla-central/rev/6e1e58e8a41d

Set release status flags based on info from the regressing bug 1689359

Thank you very much. Arrows looks good and are working.

One small issue through - every click scrolls by ~3 lines vertically or ~4 characters horizontally. Why?

Not sure off-hand, is that different from the arrow behavior from before the non-native theme landed?

(In reply to Emilio Cobos Álvarez (:emilio) from comment #10)

Not sure off-hand, is that different from the arrow behavior from before the non-native theme landed?

Ok, it was like this at least back in 78. It's good enough to be usable right now.

Thank you again for fixing arrows.

I was woried for a moment, but turns out only pref name was changed in bug 1694059 to widget.non-native-theme.gtk.scrollbar.allow-buttons

Yeah, sorry about that one :)