Extract Event clas to own file

lib/renderer/extensions/event.js

@@ -0,0 +1,24 @@
+class Event {
+  constructor () {
+    this.listeners = []
+  }
+
+  addListener (callback) {
+    this.listeners.push(callback)
+  }
+
+  removeListener (callback) {
+    const index = this.listeners.indexOf(callback)
+    if (index !== -1) {
+      this.listeners.splice(index, 1)
+    }
+  }
+
+  emit (...args) {
+    for (const listener of this.listeners) {
+      listener(...args)
+    }
+  }
+}
+
+module.exports = Event

lib/renderer/extensions/web-navigation.js

@@ -1,19 +1,5 @@
-exports.onBeforeNavigate = {
-  addListener () {
+const Event = require('./event')
 
-  },
+exports.onBeforeNavigate = new Event()
 
-  removeListener () {
-
-  }
-}
-
-exports.onCompleted = {
-  addListener () {
-
-  },
-
-  removeListener () {
-
-  }
-}
+exports.onCompleted = new Event()