Hidden windows should not keep Chrome alive.

chrome/test/data/extensions/platform_apps/hidden_then_shown/test.js

 // Copyright 2014 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.
 
 chrome.app.runtime.onLaunched.addListener(function() {
-  chrome.app.window.create('main.html', {
+  chrome.app.window.create('empty.html', {
     hidden: true,
-  }, function () {
-    chrome.test.sendMessage('Launched');
+  }, function (win) {
+    chrome.test.sendMessage('Launched', function () {
+      setTimeout(function () {
+        win.show();
+        chrome.test.sendMessage('Shown');
+      }, 3000);
+    });
   });
-});
+});