I implemented stubs in https://bugs.webkit.org/show_bug.cgi?id=135807 but that does not do the same checks as the Visual Studio build system does. Someone with access to the AppleWin internal build system needs to add the needed behavior.
Created attachment 261604 [details] Patch
Comment on attachment 261604 [details] Patch r=me
http://trac.webkit.org/changeset/190059