Restructure the ipc_fuzzer directory.

tools/ipc_fuzzer/message_replay/replay.cc

 // 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.
 
 #include <stdlib.h>
 
 #include "base/at_exit.h"
-#include "tools/ipc_fuzzer/replay/replay_process.h"
+#include "tools/ipc_fuzzer/message_replay/replay_process.h"
 
 int main(int argc, const char** argv) {
   base::AtExitManager exit_manager;
   ipc_fuzzer::ReplayProcess replay;
   if (!replay.Initialize(argc, argv))
     return EXIT_FAILURE;
 
   replay.OpenChannel();
 
   if (!replay.OpenTestcase())
     return EXIT_FAILURE;
 
   replay.Run();
   return EXIT_SUCCESS;
 }