Cast: Fix udp_transport_unittest

media/cast/test/utility/net_utility.h

 // Copyright 2014 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.
 
-#include "media/audio/mock_audio_source_callback.h"
+#include "net/base/ip_endpoint.h"
 
 namespace media {
+namespace cast {
+namespace test {
 
-MockAudioSourceCallback::MockAudioSourceCallback() {}
-MockAudioSourceCallback::~MockAudioSourceCallback() {}
+net::IPEndPoint GetFreeLocalPort();
 
+}  // namespace test
+}  // namespace cast
 }  // namespace media