Make it possible to share the embedder's dart sources for the vmservice

runtime/bin/vmservice/vmservice_sources.gypi

Index: runtime/bin/vmservice/vmservice_sources.gypi
diff --git a/runtime/bin/vmservice/vmservice_sources.gypi b/runtime/bin/vmservice/vmservice_sources.gypi
new file mode 100644
index 0000000000000000000000000000000000000000..a7d06cd741659cc49dd77bfdf598e764d3d5c69c
--- /dev/null
+++ b/runtime/bin/vmservice/vmservice_sources.gypi
@@ -0,0 +1,13 @@
+# Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+# This file contains all Dart sources for the dart:io implementation of
+# the VM Service server.
+{
+  'sources': [
+    'loader.dart',
+    'server.dart',
+    'vmservice_io.dart',
+  ],
+}