Add secure sockets to dart:io

lib/compiler/implementation/lib/io.dart

Index: lib/compiler/implementation/lib/io.dart
diff --git a/lib/compiler/implementation/lib/io.dart b/lib/compiler/implementation/lib/io.dart
index aeeff9e2e05a0038e5a342a34797d375b53cfe8e..0f381aad76e3d164ce617a5f74faf0a6f4875836 100644
--- a/lib/compiler/implementation/lib/io.dart
+++ b/lib/compiler/implementation/lib/io.dart
@@ -64,6 +64,9 @@
 #source('../../../../runtime/bin/stream_util.dart');
 #source('../../../../runtime/bin/string_stream.dart');
 #source('../../../../runtime/bin/timer_impl.dart');
+#source('../../../../runtime/bin/tls_socket.dart');
+// Uses native keyword.
+// #source('../../../../runtime/bin/tls_socket_impl.dart');
 #source('../../../../runtime/bin/websocket.dart');
 #source('../../../../runtime/bin/websocket_impl.dart');
 
@@ -210,3 +213,9 @@ const InputStream stdin = null;
 const OutputStream stdout = null;
 
 const OutputStream stderr = null;
+
+class _TlsSocket {
+  factory TlsSocket(String host, int port) {
+    throw new UnsupportedOperationException('new TlsSocket($host, $port)');
+  }
+}