cmake HAVE_VIDEO_COCOA examples

nvMcJohn/apitest thirdparty/SDL2-2.0.1/cmake/sdlchecks.cmake :504 

check_objc_source_compiles("
        #import <Cocoa/Cocoa.h>
        int main (int argc, char** argv) {}" HAVE_VIDEO_COCOA)

nvMcJohn/apitest thirdparty/SDL2-2.0.1/cmake/sdlchecks.cmake :513 

endif(HAVE_VIDEO_COCOA)