Stub in more IPC attachment brokering functionality.

ipc/attachment_broker_messages.h

Index: ipc/attachment_broker_messages.h
diff --git a/ipc/attachment_broker_messages.h b/ipc/attachment_broker_messages.h
new file mode 100644
index 0000000000000000000000000000000000000000..30ae04e385c925d316ffd0cf93ddcf28a61393d1
--- /dev/null
+++ b/ipc/attachment_broker_messages.h
@@ -0,0 +1,53 @@
+// 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_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)
+
+#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)