Add socket factory support to udp_server.c
diff --git a/binding.gyp b/binding.gyp
index 2ec5776..12ed7a8 100644
--- a/binding.gyp
+++ b/binding.gyp
@@ -657,6 +657,7 @@
         'src/core/lib/iomgr/resolve_address_windows.c',
         'src/core/lib/iomgr/resource_quota.c',
         'src/core/lib/iomgr/sockaddr_utils.c',
+        'src/core/lib/iomgr/socket_factory_posix.c',
         'src/core/lib/iomgr/socket_mutator.c',
         'src/core/lib/iomgr/socket_utils_common_posix.c',
         'src/core/lib/iomgr/socket_utils_linux.c',