Trying ken's fix for windows python
diff --git a/BUILD b/BUILD
index cfbeb39..cc48ed4 100644
--- a/BUILD
+++ b/BUILD
@@ -625,7 +625,7 @@
         "src/core/lib/iomgr/socket_utils_linux.cc",
         "src/core/lib/iomgr/socket_utils_posix.cc",
         "src/core/lib/iomgr/socket_utils_uv.cc",
-        "src/core/lib/iomgr/socket_utils_windows.c",
+        "src/core/lib/iomgr/socket_utils_windows.cc",
         "src/core/lib/iomgr/socket_windows.cc",
         "src/core/lib/iomgr/tcp_client_posix.cc",
         "src/core/lib/iomgr/tcp_client_uv.cc",