[mojo-edk] Simplify multiprocess pipe bootstrap

mojo/edk/system/ports/event.h

Index: mojo/edk/system/ports/event.h
diff --git a/mojo/edk/system/ports/event.h b/mojo/edk/system/ports/event.h
index aec9f6b43b98f26c1f425b4235edc1ceb30d4374..1dc8eab29fc4a402e2f15c67b4758a43ecd5e986 100644
--- a/mojo/edk/system/ports/event.h
+++ b/mojo/edk/system/ports/event.h
@@ -34,6 +34,7 @@ enum struct EventType : uint32_t {
   kObserveProxy,
   kObserveProxyAck,
   kObserveClosure,
+  kMergePort,
 };
 
 struct EventHeader {
@@ -63,6 +64,11 @@ struct ObserveClosureEventData {
   uint64_t last_sequence_num;
 };
 
+struct MergePortEventData {
+  PortName new_port_name;
+  PortDescriptor new_port_descriptor;
+};
+
 inline const EventHeader* GetEventHeader(const Message& message) {
   return static_cast<const EventHeader*>(message.header_bytes());
 }