Combine traits for IPC mutation and generation fuzzing plus other refactoring.

tools/ipc_fuzzer/dump/message_util.cc

 // 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 <limits.h>
 #include <stdlib.h>
 #include <iostream>
 #include <string>
 #include <vector>
 
@@ skipping 160 matching lines @@
     }
   } else {
     if (!ipc_fuzzer::MessageFile::Write(
             base::FilePath(output_file_name), output_message_vector)) {
       return EXIT_FAILURE;
     }
   }
 
   return EXIT_SUCCESS;
 }