Please keep native scrollbar support

[NoNameNeeded2]

Firefox has removed the code that is necessary to use native scrollbars in Firefox (at least in Windows, I don't know about Linux). That means that if you use a non-MS theme that comes with different scrollbars, Firefox will not (be able to) use them (even though a non-MS theme isn't a native theme per se, Firefox would consider it as "native" since it's the used theme in Windows)
They removed the code necessary because they created their own scrollbars and they thought that nobody would mind.
But I do.

So please don't delete the code in Waterfox as well.

This is the code that was deleted:
https://hg.mozilla.org/mozilla-central/rev/971c7211949d886f0ff4fa11f2d5189700084373

[NoNameNeeded2]

Just as additional info:
Leaving this code intact will not tamper with the new scrollbars that Mozilla came up with (and that are used by default also in Waterfox).
It's an additional option that can be enabled by setting this about:config setting to disabled: widget.non-native-theme.enabled
So if you want to use Mozilla's new scrollbars leave this setting in its default "enabled" position. If you want Fire-(or Waterfox) to use the scrollbars that are set in Windows, set it to disabled.
This still works in the current Waterfox version but if you choose to use the upcoming 102 ESR version as the new version, this option will no longer be available, because Mozilla has deleted the necessary code.

[NoNameNeeded2]

As it seems, the code was also deleted in G5 beta, which is a pity.

[IS4Code]

I believe this has been fixed by #3294.