IPC: Add MojoHandleAttachment

ipc/ipc_message.cc

 // Copyright (c) 2012 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 "ipc/ipc_message.h"
 
 #include "base/atomic_sequence_num.h"
 #include "base/logging.h"
 #include "build/build_config.h"
 #include "ipc/ipc_message_attachment.h"
@@ skipping 137 matching lines @@
     return false;
 
   *attachment = attachment_set->GetAttachmentAt(descriptor_index);
   return nullptr != attachment->get();
 }
 
 bool Message::HasAttachments() const {
   return attachment_set_.get() && !attachment_set_->empty();
 }
 
+bool Message::HasMojoHandles() const {
+  return attachment_set_.get() && 0 < attachment_set_->num_mojo_handles();
+}
+
 }  // namespace IPC