Revert of [mojo-edk] Simplify multiprocess pipe bootstrap

mojo/edk/system/ports/event.h

 // Copyright 2016 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 MOJO_EDK_SYSTEM_PORTS_EVENT_H_
 #define MOJO_EDK_SYSTEM_PORTS_EVENT_H_
 
 #include <stdint.h>
 
 #include "mojo/edk/system/ports/message.h"
@@ skipping 16 matching lines @@
   uint64_t last_sequence_num_to_receive;
   bool peer_closed;
 };
 
 enum struct EventType : uint32_t {
   kUser,
   kPortAccepted,
   kObserveProxy,
   kObserveProxyAck,
   kObserveClosure,
-  kMergePort,
 };
 
 struct EventHeader {
   EventType type;
   uint32_t padding;
   PortName port_name;
 };
 
 struct UserEventData {
   uint64_t sequence_num;
   uint32_t num_ports;
   uint32_t padding;
 };
 
 struct ObserveProxyEventData {
   NodeName proxy_node_name;
   PortName proxy_port_name;
   NodeName proxy_to_node_name;
   PortName proxy_to_port_name;
 };
 
 struct ObserveProxyAckEventData {
   uint64_t last_sequence_num;
 };
 
 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());
 }
 
 inline EventHeader* GetMutableEventHeader(Message* message) {
   return static_cast<EventHeader*>(message->mutable_header_bytes());
 }
 
 template <typename EventData>
 inline const EventData* GetEventData(const Message& message) {
@@ skipping 14 matching lines @@
 
 inline PortDescriptor* GetMutablePortDescriptors(UserEventData* event) {
   return reinterpret_cast<PortDescriptor*>(reinterpret_cast<char*>(event + 1));
 }
 
 }  // namespace ports
 }  // namespace edk
 }  // namespace mojo
 
 #endif  // MOJO_EDK_SYSTEM_PORTS_EVENT_H_