Adding the message writing class used for remote_security_key STDOUT communication.

remoting/host/setup/test_util.h

 // Copyright 2013 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 REMOTING_HOST_SETUP_TEST_UTIL_H_
 #define REMOTING_HOST_SETUP_TEST_UTIL_H_
 
 #include "base/files/file.h"
 
 namespace remoting {
 
 // Creates an anonymous, unidirectional pipe, returning true if successful. On
-// success, the receives ownership of both files.
+// success, the receives ownership of both files.  Uses the default buffer size
+// for the platform.
 bool MakePipe(base::File* read_file,
               base::File* write_file);
 
+// Creates an anonymous, unidirectional pipe, returning true if successful. On
+// success, the receives ownership of both files.  Uses |buffer_size_bytes| to
+// define the size of the shared buffer.
+bool MakePipe(base::File* read_file,
+              base::File* write_file,
+              unsigned int buffer_size_bytes);
+
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_SETUP_TEST_UTIL_H_