<AWT Dev> questions about JDK-8181910 [macos] Support dark title bars on macOS
I gather that this change was reverted, but why does the bug report  not refect that?
Also, I believe the proposed change is incorrect, above and beyond its build-breaking feature.
(1) It installs the appearances NSAppearanceNameVibrantLight and NSAppearanceNameVibrantDark, which are inappropriate.
From the AppKit documentation:
Don't assign an NSAppearance object with this type directly to one of your views. Instead, assign a light appearance to your view, make sure its allowsVibrancy property is set to YES, and embed the view in a visual effect view. When you do, AppKit updates your view's appearance to this type.
(2) In macOS 10.14, setting an explicit appearance will override the system-provided default. There needs to be a way to prevent AWT from setting the appearance attribute.
(3) Dynamic changes to the client property apparently will not work, because _STYLE_PROP_BITMASK is not extended with the new style bit.