fix: quit after Chromium is fully started (#21488)

* fix: quit when chromium is fully started

* test: remove hacks on app.quit

* chore: RunUntilIdle is unnecessary

spec/fixtures/api/command-line/main.js

@@ -9,7 +9,5 @@ app.on('ready', () => {
   process.stdout.write(JSON.stringify(payload))
   process.stdout.end()
 
-  setImmediate(() => {
-    app.quit()
-  })
+  app.quit()
 })

spec/fixtures/api/cookie-app/main.js

@@ -42,8 +42,6 @@ app.on('ready', async function () {
   } finally {
     process.stdout.end()
 
-    setImmediate(() => {
-      app.quit()
-    })
+    app.quit()
   }
 })

spec/fixtures/api/ipc-main-listeners/main.js

@@ -4,7 +4,5 @@ app.on('ready', () => {
   process.stdout.write(JSON.stringify(ipcMain.eventNames()))
   process.stdout.end()
 
-  setImmediate(() => {
-    app.quit()
-  })
+  app.quit()
 })

spec/fixtures/api/leak-exit-browserview.js

@@ -2,5 +2,5 @@ const { BrowserView, app } = require('electron')
 app.on('ready', function () {
   new BrowserView({})  // eslint-disable-line
 
-  process.nextTick(() => app.quit())
+  app.quit()
 })

spec/fixtures/api/leak-exit-webcontents.js

@@ -2,5 +2,5 @@ const { app, webContents } = require('electron')
 app.on('ready', function () {
   webContents.create({})
 
-  process.nextTick(() => app.quit())
+  app.quit()
 })

spec/fixtures/api/locale-check/main.js

@@ -4,7 +4,5 @@ app.on('ready', () => {
   process.stdout.write(app.getLocale())
   process.stdout.end()
 
-  setImmediate(() => {
-    app.quit()
-  })
+  app.quit()
 })