content: Pass IOSurface references using Mach IPC.

content/common/mac/io_surface_manager_token.h

Index: content/common/mac/io_surface_manager_token.h
diff --git a/content/common/mac/io_surface_manager_token.h b/content/common/mac/io_surface_manager_token.h
new file mode 100644
index 0000000000000000000000000000000000000000..cdaebf6568cf87eef0b981e032f573e8e6e38897
--- /dev/null
+++ b/content/common/mac/io_surface_manager_token.h
@@ -0,0 +1,16 @@
+// 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.
+
+#ifndef CONTENT_COMMON_MAC_IO_SURFACE_MANAGER_TOKEN_H_
+#define CONTENT_COMMON_MAC_IO_SURFACE_MANAGER_TOKEN_H_
+
+#include "gpu/command_buffer/common/mailbox.h"
+
+namespace content {
+
+using IOSurfaceManagerToken = gpu::Mailbox;
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_MAC_IO_SURFACE_MANAGER_TOKEN_H_