[Chromecast] Ignore interfaces not used to connect to internet.

chromecast/net/net_util_cast.h

Index: chromecast/net/net_util_cast.h
diff --git a/chromecast/net/net_util_cast.h b/chromecast/net/net_util_cast.h
new file mode 100644
index 0000000000000000000000000000000000000000..2ec95bbd985a7b15ab6da890c2ccd8ddbfa9a48f
--- /dev/null
+++ b/chromecast/net/net_util_cast.h
@@ -0,0 +1,20 @@
+// Copyright 2015 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.
+
+#ifndef CHROMECAST_NET_NET_UTIL_H_
+#define CHROMECAST_NET_NET_UTIL_H_
+
+#include <string>
+
+#include "base/containers/hash_tables.h"
+
+namespace chromecast {
+
+// Gets the list of interfaces that should be ignored. The interfaces returned
+// by this function will not be used to connect to the internet.
+base::hash_set<std::string> GetIgnoredInterfaces();
+
+}  // namespace chromecast
+
+#endif  // CHROMECAST_NET_NET_UTIL_CAST_H_