After committing this change: https://bugs.webkit.org/show_bug.cgi?id=66495 Lion-specific scroller SPIs can use forward declaration instead of WebKitSystemInterface some re-names are in order. USE(WK_Scrollbar_Painter), WKScrollbarPainterRef, and WKScrollbarPainterControllerRef all need to be re-named to remove references to WebKitSystemInterface since the implementation is now in WebCore, and the type names should sound more Objective-Cish instead of C++ish.
Created attachment 104564 [details] Patch
Thanks Sam! Committed change with revision 93445.