If the scrollbar pseudo-elements are used to change the appearance of the scrollbar, live changes to the applicable styles are not applied immediately. Instead, the parts of the scrollbar must be hovered, at which point they will change their appearance. See the attached testcase for an example. A button is used to toggle a 'dark' class on the document element. Different styles apply to the body and the scrollbar when this class is present, but the new scrollbar styles are not picked up immediately, instead it retains the old appearance until it is hovered. Browser: Google Chrome 27.0.1453.9 (Official Build 191205) dev-m OS: Windows 7 WebKit: 537.36 (@146919)
Created attachment 196031 [details] Simple testcase
Safari and Chrome both handle this test case properly.
Reopening since it has PR - https://github.com/WebKit/WebKit/pull/12312
Committed 264356@main (dfd97e668d4a): <https://commits.webkit.org/264356@main> Reviewed commits have been landed. Closing PR #12312 and removing active labels.
<rdar://problem/109674102>