Make calculator app handle onRestarted events.

chrome/common/extensions/docs/examples/apps/calculator/app/controller.js

 /**
  * Copyright (c) 2012 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.
  **/
 
 // Checking for "chrome.app.runtime" availability allows this Chrome app code to
 // be tested in a regular web page (like tests/manual.html). Checking for
 // "chrome" and "chrome.app" availability further allows this code to be tested
 // in non-Chrome browsers, which is useful for example to test touch support
 // with a non-Chrome touch device.
 if (typeof chrome !== 'undefined' && chrome.app && chrome.app.runtime) {
-  chrome.app.runtime.onLaunched.addListener(function() {
+  var showCalculatorWindow = function () {
     chrome.app.window.create('calculator.html', {
       defaultWidth: 243, minWidth: 243, maxWidth: 243,
       defaultHeight: 380, minHeight: 380, maxHeight: 380,
       id: 'calculator'
     }, function(appWindow) {
       appWindow.contentWindow.onload = function() {
         new Controller(new Model(9), new View(appWindow.contentWindow));
       };
+
+      chrome.storage.local.set({windowVisible: true});
+      appWindow.onClosed.addListener(function() {
+        chrome.storage.local.set({windowVisible: false});
+      });
+    });
+  }
+
+  chrome.app.runtime.onLaunched.addListener(showCalculatorWindow);
+  chrome.app.runtime.onRestarted.addListener(function() {
+    chrome.storage.local.get('windowVisible', function(data) {
+      if (data.windowVisible)
+        showCalculatorWindow();
     });
   });
 }
 
 function Controller(model, view) {
   this.inputs = this.defineInputs_();
   this.model = model;
   this.view = view;
   this.view.onButton = function(button) {
     this.handleInput_(this.inputs.byButton[button]);
@@ skipping 61 matching lines @@
     operand: this.getUpdatedValue_(before, after, 'operand', !before.operator)
   });
   return !before.accumulator;
 }
 
 /** @private */
 Controller.prototype.getUpdatedValue_ = function(before, after, key, zero) {
   var value = (typeof after[key] !== 'undefined') ? after[key] : before[key];
   return zero ? (value || '0') : value;
 }