Simplify the magic required to create IPC message headers a bit.

chrome/browser/importer/firefox_importer_unittest_messages_internal.h

 // Copyright (c) 2009 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.
 
-// This header is meant to be included in multiple passes, hence no traditional
-// header guard.
-// See ipc_message_macros.h for explanation of the macros and passes.
+#include "ipc/ipc_message_macros.h"
 
-#include "ipc/ipc_message_macros.h"
+#define IPC_MESSAGE_START FirefoxImporterUnittestMsgStart
 
 // Messages definitions for messages sent between the unit test binary and
 // a child process by FFUnitTestDecryptorProxy.
 IPC_BEGIN_MESSAGES(Test)
 
 // Server->Child: Initialize the decrytor with the following paramters.
 IPC_MESSAGE_CONTROL2(Msg_Decryptor_Init,
                      std::wstring /* dll_path */,
                      std::wstring /* db_path */)
 // Child->Server: Return paramter from init call.
 IPC_MESSAGE_CONTROL1(Msg_Decryptor_InitReturnCode,
                      bool /* ret */)
 
 // Server->Child: Decrypt a given string.
 IPC_MESSAGE_CONTROL1(Msg_Decrypt,
                      std::string /* crypt */)
 // Child->Server: Decrypted String.
 IPC_MESSAGE_CONTROL1(Msg_Decryptor_Response,
                      string16 /* unencrypted_str */)
 
 // Server->Child: Die.
 IPC_MESSAGE_CONTROL0(Msg_Decryptor_Quit)
-
-IPC_END_MESSAGES(Test)