IPC: Add MojoHandleAttachment

ipc/mojo/ipc_mojo_handle_attachment.cc

+// 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_handle_attachment.h"
+
+#include "ipc/ipc_message_attachment_set.h"
+#include "third_party/mojo/src/mojo/edk/embedder/embedder.h"
+
+namespace IPC {
+namespace internal {
+
+MojoHandleAttachment::MojoHandleAttachment(mojo::ScopedHandle handle)
+    : handle_(handle.Pass()) {
+}
+
+MojoHandleAttachment::~MojoHandleAttachment() {
+}
+
+MessageAttachment::Type MojoHandleAttachment::GetType() const {
+  return TYPE_MOJO_HANDLE;
+}
+
+#if defined(OS_POSIX)
+base::PlatformFile MojoHandleAttachment::TakePlatformFile() {
+  mojo::embedder::ScopedPlatformHandle platform_handle;
+  MojoResult unwrap_result = mojo::embedder::PassWrappedPlatformHandle(
+      handle_.release().value(), &platform_handle);
+  if (unwrap_result != MOJO_RESULT_OK) {
+    DLOG(ERROR) << "Pipe failed to covert handles. Closing: " << unwrap_result;
+    return -1;
+  }
+
+  return platform_handle.release().fd;
+}
+#endif  // OS_POSIX
+
+mojo::ScopedHandle MojoHandleAttachment::TakeHandle() {
+  return handle_.Pass();
+}
+
+}  // namespace internal
+}  // namespace IPC