[ChromeOS] Auto reload auth extension.

chrome/browser/resources/chromeos/login/screen_gaia_signin.js

 // Copyright (c) 2011 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.
 
 /**
  * @fileoverview Oobe signin screen implementation.
  */
 
 cr.define('login', function() {
 
@@ skipping 14 matching lines @@
     window.addEventListener('message',
                             screen.onMessage_.bind(screen), false);
   };
 
   GaiaSigninScreen.prototype = {
     __proto__: HTMLDivElement.prototype,
 
     // Authentication extension's start page URL.
     extension_url_: null,
 
+    // Number of times that we reload extension frame.
+    retryCount_: 0,
+
+    // Timer id of pending retry.
+    retryTimer_: undefined,
+
     /** @inheritDoc */
     decorate: function() {
       $('createAccount').innerHTML = localStrings.getStringF(
           'createAccount',
           '<a id="createAccountLink" class="signin-link" href="#">',
           '</a>');
       $('guestSignin').innerHTML = localStrings.getStringF(
           'guestSignin',
           '<a id="guestSigninLink" class="signin-link" href="#">',
           '</a>');
@@ skipping 74 matching lines @@
 
       // Announce the name of the screen, if accessibility is on.
       $('gaia-signin-aria-label').setAttribute(
           'aria-label', localStrings.getString('signinScreenTitle'));
 
       // Button header is always visible when sign in is presented.
       // Header is hidden once GAIA reports on successful sign in.
       Oobe.getInstance().headerHidden = false;
 
       this.loading = true;
+      this.clearRetry_();
     },
 
     /**
      * Checks if message comes from the loaded authentication extension.
      * @param e {object} Payload of the received HTML5 message.
      * @type {bool}
      */
     isAuthExtMessage_: function(e) {
       return this.extension_url_ != null &&
           this.extension_url_.indexOf(e.origin) == 0 &&
           e.source == $('signin-frame').contentWindow;
     },
 
     /**
      * Event handler that is invoked when HTML5 message is received.
      * @param e {object} Payload of the received HTML5 message.
      */
     onMessage_: function(e) {
       var msg = e.data;
       if (msg.method == 'completeLogin' && this.isAuthExtMessage_(e)) {
         chrome.send('completeLogin', [msg.email, msg.password] );
         this.loading = true;
         // Now that we're in logged in state header should be hidden.
         Oobe.getInstance().headerHidden = true;
       } else if (msg.method == 'loginUILoaded' && this.isAuthExtMessage_(e)) {
         $('offline-message').update();
         this.loading = false;
+        this.clearRetry_();
         chrome.send('loginWebuiReady');
       }
     },
 
     /**
      * Clears input fields and switches to input mode.
      * @param {boolean} takeFocus True to take focus.
      */
     reset: function(takeFocus) {
       // Reload and show the sign-in UI if needed.
       if (takeFocus)
         Oobe.showSigninUI();
+    },
+
+    /**
+     * Clears retry data.
+     * @private
+     */
+    clearRetry_: function() {
+      this.retryCount_ = 0;
+      if (this.retryTimer_) {
+        window.clearTimeout(this.retryTimer_);
+        this.retryTimer_ = undefined;
+      }
+    },
+
+    /**
+     * Reloads extension frame.
+     * @private
+     */
+    doReload_: function() {
+      console.log('Reload auth extension frame.');
+      $('signin-frame').src = this.extension_url_;
+      this.retryTimer_ = undefined;
+    },
+
+    /**
+     * Schedules extension frame reload.
+     */
+    schdeduleRetry: function() {
+      if (this.retryCount_ >= 3 || this.retryTimer_)
+        return;
+
+      const MAX_DELAY = 7200;  // 7200 seconds (i.e. 2 hours)
+      const MIN_DELAY = 1;  // 1 second
+
+      var delay = Math.pow(2, this.retryCount_) * 5;
+      delay = Math.max(MIN_DELAY, Math.min(MAX_DELAY, delay)) * 1000;
+
+      ++this.retryCount_;
+      this.retryTimer_ = window.setTimeout(this.doReload_.bind(this), delay);
+      console.log('GaiaSigninScreen schdeduleRetry in ' + delay + 'ms.');
     }
   };
 
   return {
     GaiaSigninScreen: GaiaSigninScreen
   };
 });