feat: MessagePorts in the main process (#22404)

lib/browser/message-port-main.ts

@@ -0,0 +1,25 @@
+import { EventEmitter } from 'events'
+
+export class MessagePortMain extends EventEmitter {
+  _internalPort: any
+  constructor (internalPort: any) {
+    super()
+    this._internalPort = internalPort
+    this._internalPort.emit = (channel: string, event: {ports: any[]}) => {
+      if (channel === 'message') { event = { ...event, ports: event.ports.map(p => new MessagePortMain(p)) } }
+      this.emit(channel, event)
+    }
+  }
+  start () {
+    return this._internalPort.start()
+  }
+  close () {
+    return this._internalPort.close()
+  }
+  postMessage (...args: any[]) {
+    if (Array.isArray(args[1])) {
+      args[1] = args[1].map((o: any) => o instanceof MessagePortMain ? o._internalPort : o)
+    }
+    return this._internalPort.postMessage(...args)
+  }
+}