RFR: 8295242: ScrollBarSkin: memory leak when changing skin

[Andy Goryachev]

On Wed, 12 Oct 2022 23:18:46 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

> Fixed memory leak when changing skin in ScrollBarSkin (was adding an event handler without removing it in dispose()).
> 
> This change depends on ListenerHelper PR
> https://github.com/openjdk/jfx/pull/908

changes will be reviewed as a part of https://github.com/openjdk/jfx/pull/928

-------------

PR: https://git.openjdk.org/jfx/pull/914