Cast: Fix udp_transport_unittest

media/cast/test/utility/net_utility.cc

Index: media/cast/test/utility/net_utility.cc
diff --git a/media/cast/test/utility/net_utility.cc b/media/cast/test/utility/net_utility.cc
new file mode 100644
index 0000000000000000000000000000000000000000..57899310facbd21cfaac63cf50c0e29817416c8e
--- /dev/null
+++ b/media/cast/test/utility/net_utility.cc
@@ -0,0 +1,39 @@
+// 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/cast/test/utility/net_utility.h"
+
+#include "base/basictypes.h"
+#include "net/base/net_errors.h"
+#include "net/udp/udp_socket.h"
+
+namespace media {
+namespace cast {
+namespace test {
+
+// TODO(hubbe): Move to /net/.
+net::IPEndPoint GetFreeLocalPort() {
+  // Determine a unused UDP port for the in-process receiver to listen on.

[miu, 2014/05/15 02:48:48]

nit: IMHO, these 3 lines of comments would be more helpful in the .h file.

[hubbe, 2014/05/16 01:04:45]

Done.

+  // Method: Bind a UDP socket on port 0, and then check which port the
+  // operating system assigned to it.
+  net::IPAddressNumber localhost;
+  localhost.push_back(127);
+  localhost.push_back(0);
+  localhost.push_back(0);
+  localhost.push_back(1);
+  scoped_ptr<net::UDPSocket> receive_socket(
+      new net::UDPSocket(net::DatagramSocket::DEFAULT_BIND,
+                         net::RandIntCallback(),
+                         NULL,
+                         net::NetLog::Source()));
+  receive_socket->AllowAddressReuse();
+  CHECK_EQ(net::OK, receive_socket->Bind(net::IPEndPoint(localhost, 0)));
+  net::IPEndPoint endpoint;
+  CHECK_EQ(net::OK, receive_socket->GetLocalAddress(&endpoint));
+  return endpoint;
+}
+
+}  // namespace test
+}  // namespace cast
+}  // namespace media