[macosx] Low-level error on OS X 10.11 with DnD in Swing

Run some jdk9 build, before or after b111 (I tried b107 and b113) on the attached test on OS X 10.11. Immediately on start of the drag gesture there will be a native error:
_initWithWindowNumber: error creating graphics ctxt object for ctxt:0xc5a3, window:0x91

It is not reproducible on OS X 10.10. Functionality works as well but some research seems necessary.