all main modules have init() function

main/windows.js

@@ -9,12 +9,6 @@ var electron = require('electron')
 
 var app = electron.app
 
-var isQuitting = false
-
-app.on('before-quit', function () {
-  isQuitting = true
-})
-
 function createMainWindow (menu) {
   var win = windows.main = new electron.BrowserWindow({
     autoHideMenuBar: true, // Hide top menu bar unless Alt key is pressed (Windows, Linux)
@@ -46,7 +40,7 @@ function createMainWindow (menu) {
   win.on('leave-full-screen', () => menu.onToggleFullScreen(false))
 
   win.on('close', function (e) {
-    if (process.platform === 'darwin' && !isQuitting) {
+    if (process.platform === 'darwin' && !app.isQuitting) {
       e.preventDefault()
       // sendSync() ensures that video will pause before window is hidden, at which point
       // the update() loop (which uses requestAnimationFrame) ceases to run