IPC: Add MojoHandleAttachment

ipc/mojo/ipc_mojo_message_helper.cc

Index: ipc/mojo/ipc_mojo_message_helper.cc
diff --git a/ipc/mojo/ipc_mojo_message_helper.cc b/ipc/mojo/ipc_mojo_message_helper.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c6f6dbfa594affe7b4233bda288088536700667c
--- /dev/null
+++ b/ipc/mojo/ipc_mojo_message_helper.cc
@@ -0,0 +1,47 @@
+// Copyright (c) 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.
+
+#include "ipc/mojo/ipc_mojo_message_helper.h"
+
+#include "ipc/mojo/ipc_mojo_handle_attachment.h"
+
+namespace IPC {
+
+// static
+bool MojoMessageHelper::WriteMessagePipeTo(
+    Message* message,
+    mojo::ScopedMessagePipeHandle handle) {
+  message->WriteAttachment(new internal::MojoHandleAttachment(
+      mojo::ScopedHandle::From(handle.Pass())));
+  return true;
+}
+
+// static
+bool MojoMessageHelper::ReadMessagePipeFrom(
+    const Message* message,
+    PickleIterator* iter,
+    mojo::ScopedMessagePipeHandle* handle) {
+  scoped_refptr<MessageAttachment> attachment;
+  if (!message->ReadAttachment(iter, &attachment)) {
+    DLOG(ERROR) << "Failed to read attachment for message pipe.";
+    return false;
+  }
+
+  if (attachment->GetType() != MessageAttachment::TYPE_MOJO_HANDLE) {
+    DLOG(ERROR) << "Unxpected attachment type:" << attachment->GetType();
+    return false;
+  }
+
+  handle->reset(mojo::MessagePipeHandle(
+      static_cast<internal::MojoHandleAttachment*>(attachment.get())
+          ->TakeHandle()
+          .release()
+          .value()));
+  return true;
+}
+
+MojoMessageHelper::MojoMessageHelper() {
+}
+
+}  // namespace IPC