Add secure sockets to dart:io

lib/compiler/implementation/lib/io_patch.dart

Index: lib/compiler/implementation/lib/io_patch.dart
diff --git a/lib/compiler/implementation/lib/io_patch.dart b/lib/compiler/implementation/lib/io_patch.dart
index f603e87df339088dffde2d1342f72a32fef48637..0896c7f33282a6cbe91e5c0b6077afaeb24ca044 100644
--- a/lib/compiler/implementation/lib/io_patch.dart
+++ b/lib/compiler/implementation/lib/io_patch.dart
@@ -167,6 +167,10 @@ patch class Socket {
   patch factory Socket(String host, int port) => new _Socket(host, port);
 }
 
+patch class TlsSocket {
+  patch factory TlsSocket(String host, int port) => new _TlsSocket(host, port);
+}
+
 patch class _StdIOUtils {
   patch static _getStdioHandle(Socket socket, int num) {
     throw new UnsupportedError("StdIOUtils._getStdioHandle");