Add a dependency for FlatBuffers.

third_party/flatbuffers/flatc_wrapper.py

Index: third_party/flatbuffers/flatc_wrapper.py
diff --git a/third_party/flatbuffers/flatc_wrapper.py b/third_party/flatbuffers/flatc_wrapper.py
new file mode 100755
index 0000000000000000000000000000000000000000..8f4a6d795c79bfe2524ed8b4966bf8154db434ea
--- /dev/null
+++ b/third_party/flatbuffers/flatc_wrapper.py
@@ -0,0 +1,17 @@
+#!/usr/bin/env python
+# Copyright (c) 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+A simple wrapper to flatc, executes whatever is passed as parameters.
+"""
+
+import subprocess
+import sys
+
+def main(args):
+  return subprocess.call(args[1:])
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))