Step two of optionally sending messages to/from message ports as base::Value.

content/public/common/message_port_types.h

Index: content/public/common/message_port_types.h
diff --git a/content/public/common/message_port_types.h b/content/public/common/message_port_types.h
index 961afe22a5e8d3fad5d4b063c69a3d6fca6bb446..cf53d088dc49102189a60105fcd491f723626a2f 100644
--- a/content/public/common/message_port_types.h
+++ b/content/public/common/message_port_types.h
@@ -11,6 +11,7 @@
 #include "base/strings/string16.h"
 #include "base/values.h"
 #include "content/common/content_export.h"
+#include "ipc/ipc_message.h"
 
 namespace content {
 
@@ -37,6 +38,11 @@ struct CONTENT_EXPORT MessagePortMessage {
   base::ListValue message_as_value;
 };
 
+struct TransferredMessagePort {
+  int id = MSG_ROUTING_NONE;
+  bool send_messages_as_values = false;
+};
+
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_COMMON_MESSAGE_PORT_TYPES_H_