+ // KH: We cannot let this be called directly since the metal appearance is now managed by an
+ // extra style. Calling this function directly can result in blank white window backgrounds.
+ // This is because the ExtraStyle flags get out of sync with the metal appearance and the metal
+ // logic & checks cease to work as expected. To set the metal appearance, use SetExtraStyle.
+ void MacSetMetalAppearance( bool on ) ;
+