Revise based on Mark's comments.
diff --git a/binding.gyp b/binding.gyp
index 3444fa5..b64ff58 100644
--- a/binding.gyp
+++ b/binding.gyp
@@ -822,6 +822,7 @@
'src/core/tsi/fake_transport_security.c',
'src/core/tsi/ssl_transport_security.c',
'src/core/tsi/transport_security.c',
+ 'src/core/tsi/transport_security_adapter.c',
'src/core/ext/transport/chttp2/server/chttp2_server.c',
'src/core/ext/transport/chttp2/client/secure/secure_channel_create.c',
'src/core/ext/filters/client_channel/channel_connectivity.c',