Make attachment broker a subclass of IPC::Listener.

ipc/attachment_broker_messages.h

 // Copyright 2015 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.
 
 // IPC messages used by the attachment broker.
 // Multiply-included message file, hence no include guard.
 
 #include "ipc/brokerable_attachment.h"
+#include "ipc/ipc_export.h"
 #include "ipc/ipc_message_macros.h"
 
 #if defined(OS_WIN)
 #include "ipc/handle_attachment_win.h"
 #endif  // defined(OS_WIN)
 
 // ----------------------------------------------------------------------------
 // Serialization of structs.
 // ----------------------------------------------------------------------------
 
 #if defined(OS_WIN)
 IPC_STRUCT_TRAITS_BEGIN(IPC::internal::HandleAttachmentWin::WireFormat)
 IPC_STRUCT_TRAITS_MEMBER(handle)
 IPC_STRUCT_TRAITS_MEMBER(destination_process)
 IPC_STRUCT_TRAITS_MEMBER(attachment_id)
 IPC_STRUCT_TRAITS_END()
 #endif  // defined(OS_WIN)
 
+#undef IPC_MESSAGE_EXPORT
+#define IPC_MESSAGE_EXPORT IPC_EXPORT
 #define IPC_MESSAGE_START AttachmentBrokerMsgStart
 
 // ----------------------------------------------------------------------------
 // Messages sent from the broker to a non-broker process.
 // ----------------------------------------------------------------------------
 
 #if defined(OS_WIN)
 // Sent from a broker to a non-broker to indicate that a windows HANDLE has been
 // brokered. Contains all information necessary for the non-broker to translate
 // a BrokerAttachment::AttachmentId to a BrokerAttachment.
 IPC_MESSAGE_CONTROL1(
     AttachmentBrokerMsg_WinHandleHasBeenDuplicated,
     IPC::internal::HandleAttachmentWin::WireFormat /* wire_format */)
 #endif  // defined(OS_WIN)
 
 // ----------------------------------------------------------------------------
 // Messages sent from a non-broker process to a broker process.
 // ----------------------------------------------------------------------------
 
 #if defined(OS_WIN)
 // Sent from a non-broker to a broker to request the duplication of a HANDLE
 // into a different process (possibly the broker process, or even the original
 // process).
 IPC_MESSAGE_CONTROL1(
     AttachmentBrokerMsg_DuplicateWinHandle,
     IPC::internal::HandleAttachmentWin::WireFormat /* wire_format */)
 #endif  // defined(OS_WIN)