Revise based on Mark's comments.
diff --git a/grpc.gemspec b/grpc.gemspec
index 6a20468..abbd6f4 100755
--- a/grpc.gemspec
+++ b/grpc.gemspec
@@ -323,6 +323,7 @@
s.files += %w( src/core/tsi/ssl_transport_security.h )
s.files += %w( src/core/tsi/ssl_types.h )
s.files += %w( src/core/tsi/transport_security.h )
+ s.files += %w( src/core/tsi/transport_security_adapter.h )
s.files += %w( src/core/tsi/transport_security_interface.h )
s.files += %w( src/core/ext/transport/chttp2/server/chttp2_server.h )
s.files += %w( src/core/ext/filters/client_channel/client_channel.h )
@@ -547,6 +548,7 @@
s.files += %w( src/core/tsi/fake_transport_security.c )
s.files += %w( src/core/tsi/ssl_transport_security.c )
s.files += %w( src/core/tsi/transport_security.c )
+ s.files += %w( src/core/tsi/transport_security_adapter.c )
s.files += %w( src/core/ext/transport/chttp2/server/chttp2_server.c )
s.files += %w( src/core/ext/transport/chttp2/client/secure/secure_channel_create.c )
s.files += %w( src/core/ext/filters/client_channel/channel_connectivity.c )