Fix resource leak on extension window closing.

chrome/browser/resources/chromeos/arc_support/background.js

 // Copyright 2016 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.
 
 /**
  * UI Pages. Note the order must be in sync with the ArcAuthService::UIPage
  * enum.
  * @type {Array<string>}
  */
 var UI_PAGES = ['none',
@@ skipping 23 matching lines @@
  */
 var termsView = null;
 
 /**
  * Used for bidirectional communication with native code.
  * @type {chrome.runtime.Port}
  */
 var port = null;
 
 /**
- * Indicates that window was closed internally and it is not required to send
- * closure notification.
- * @type {boolean}
- */
-var windowClosedInternally = false;
-
-/**
- * Timer for terms reload.
- * @type {Object}
- */
-var termsReloadTimeout = null;
-
-/**
  * Stores current device id.
  * @type {string}
  */
 var currentDeviceId = null;
 
 /**
  * Indicates that terms were accepted by user.
  * @type {boolean}
  */
 var termsAccepted = false;
@@ skipping 17 matching lines @@
 var INNER_WIDTH = 960;
 
 /**
  * Host window inner default height.
  * @const {number}
  */
 var INNER_HEIGHT = 688;
 
 
 /**
- * Closes current window in response to request from native code. This does not
- * issue 'cancelAuthCode' message to native code.
- */
-function closeWindowInternally() {
-  windowClosedInternally = true;
-  appWindow.close();
-  appWindow = null;
-}
-
-/**
  * Sends a native message to ArcSupportHost.
  * @param {string} code The action code in message.
  * @param {Object=} opt_Props Extra properties for the message.
  */
 function sendNativeMessage(code, opt_Props) {
   var message = Object.assign({'action': code}, opt_Props);
   port.postMessage(message);
 }
 
 /**
@@ skipping 180 matching lines @@
   }
 
   if (message.action == 'initialize') {
     initialize(message.data, message.deviceId);
   } else if (message.action == 'setMetricsMode') {
     setMetricsMode(message.text, message.canEnable, message.on);
   } else if (message.action == 'setBackupAndRestoreMode') {
     setBackupRestoreMode(message.enabled, message.managed);
   } else if (message.action == 'setLocationServiceMode') {
     setLocationServiceMode(message.enabled, message.managed);
-  } else if (message.action == 'closeUI') {
-    closeWindowInternally();
+  } else if (message.action == 'closeWindow') {
+    if (appWindow) {
+      appWindow.close();
+    }
   } else if (message.action == 'showPage') {
     showPageWithStatus(message.page, message.status);
   } else if (message.action == 'setWindowBounds') {
     setWindowBounds();
   }
 }
 
 /**
  * Connects to ArcSupportHost.
  */
 function connectPort() {
   var hostName = 'com.google.arc_support';
   port = chrome.runtime.connectNative(hostName);
   port.onMessage.addListener(onNativeMessage);
 }
 
 /**
- * Shows requested page and hide others. Show appWindow if it was hidden before
- * for non 'none' pages. For 'none' page this closes host window.
+ * Shows requested page and hide others. Show appWindow if it was hidden before.
+ * 'none' hides all views.
  * @param {string} pageDivId id of divider of the page to show.
  */
 function showPage(pageDivId) {
   if (!appWindow) {
     return;
   }
 
-  if (pageDivId == 'none') {
-    closeWindowInternally();
-    return;
-  }
-
   var doc = appWindow.contentWindow.document;
   var pages = doc.getElementsByClassName('section');
   var sendFeedbackElement = doc.getElementById('button-send-feedback');
   if (pageDivId == 'error-with-feedback') {
     // Only show feedback button if the pageDivId is 'error-with-feedback'.
     sendFeedbackElement.hidden = false;
     pageDivId = 'error';
   } else {
     sendFeedbackElement.hidden = true;
   }
@@ skipping 223 matching lines @@
       var enableLocationService = doc.getElementById('enable-location-service');
       sendNativeMessage('setLocationService', {
         'enabled': enableLocationService.checked
       });
 
       sendNativeMessage('startLso');
     };
 
     var onCancel = function() {
       if (appWindow) {
-        windowClosedInternally = false;
         appWindow.close();
-        appWindow = null;
       }
     };
 
     var onRetry = function() {
       if (termsAccepted) {
         sendNativeMessage('startLso');
       } else {
         loadInitialTerms();
       }
     };
 
     var onSendFeedback = function() {
       sendNativeMessage('sendFeedback');
     };
 
     doc.getElementById('button-agree').addEventListener('click', onAgree);
     doc.getElementById('button-cancel').addEventListener('click', onCancel);
     doc.getElementById('button-retry').addEventListener('click', onRetry);
     doc.getElementById('button-send-feedback')
         .addEventListener('click', onSendFeedback);
 
     connectPort();
   };
 
   var onWindowCreated = function(createdWindow) {
     appWindow = createdWindow;
     appWindow.contentWindow.onload = onAppContentLoad;
-    createdWindow.onClosed.addListener(onWindowClosed);
+    appWindow.onClosed.addListener(onWindowClosed);
 
     setWindowBounds();
   };
 
   var onWindowClosed = function() {
-    if (termsReloadTimeout) {
-      clearTimeout(termsReloadTimeout);
-      termsReloadTimeout = null;
-    }
+    appWindow = null;
 
-    if (windowClosedInternally) {
-      return;
-    }
-    sendNativeMessage('cancelAuthCode');
+    // Notify to Chrome.
+    sendNativeMessage('onWindowClosed');
+
+    // On window closed, then dispose the extension. So, close the port
+    // otherwise the background page would be kept alive so that the extension
+    // would not be unloaded.
+    port.disconnect();
+    port = null;
   };
 
-  windowClosedInternally = false;
-
   var options = {
     'id': 'play_store_wnd',
     'resizable': false,
     'hidden': true,
     'frame': {
       type: 'chrome',
       color: '#ffffff'
     },
     'innerBounds': {
       'width': INNER_WIDTH,
       'height': INNER_HEIGHT
     }
   };
   chrome.app.window.create('main.html', options, onWindowCreated);
 });