Added more typechecking functions and unit tests for existing code.

remoting/webapp/app_remoting/js/app_remoting.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.
 
 /**
  * @fileoverview
  * This class implements the functionality that is specific to application
  * remoting ("AppRemoting" or AR).
  */
 
@@ skipping 297 matching lines @@
 /**
  * @param {string} type The message type.
  * @param {Object} message The parsed extension message data.
  */
 remoting.AppRemoting.prototype.onExtensionMessage = function(type, message) {
   switch (type) {
 
     case 'openURL':
       // URL requests from the hosted app are untrusted, so disallow anything
       // other than HTTP or HTTPS.
-      var url = getStringAttr(message, 'url');
+      var url = base.getStringAttr(message, 'url');
       if (url.indexOf('http:') != 0 && url.indexOf('https:') != 0) {
         console.error('Bad URL: ' + url);
       } else {
         window.open(url);
       }
       return true;
 
     case 'onWindowRemoved':
-      var id = getNumberAttr(message, 'id');
+      var id = base.getNumberAttr(message, 'id');
       this.windowActivationMenu_.remove(id);
       return true;
 
     case 'onWindowAdded':
-      var id = getNumberAttr(message, 'id');
-      var title = getStringAttr(message, 'title');
+      var id = base.getNumberAttr(message, 'id');
+      var title = base.getStringAttr(message, 'title');
       this.windowActivationMenu_.add(id, title);
       return true;
 
     case 'onAllWindowsMinimized':
       chrome.app.window.current().minimize();
       return true;
 
     case 'setKeyboardLayouts':
-      var supportedLayouts = getArrayAttr(message, 'supportedLayouts');
-      var currentLayout = getStringAttr(message, 'currentLayout');
+      var supportedLayouts = base.getArrayAttr(message, 'supportedLayouts');
+      var currentLayout = base.getStringAttr(message, 'currentLayout');
       console.log('Current host keyboard layout: ' + currentLayout);
       console.log('Supported host keyboard layouts: ' + supportedLayouts);
       this.keyboardLayoutsMenu_.setLayouts(supportedLayouts, currentLayout);
       return true;
 
     case 'pingResponse':
-      var then = getNumberAttr(message, 'timestamp');
+      var then = base.getNumberAttr(message, 'timestamp');
       var now = new Date().getTime();
       this.contextMenu_.updateConnectionRTT(now - then);
       return true;
   }
 
   return false;
 };
 
 /**
  * Called when an error needs to be displayed to the user.
  *
  * @param {!remoting.Error} error The error to be localized and displayed.
  * @return {void} Nothing.
  */
 remoting.AppRemoting.prototype.handleError = function(error) {
   console.error('Connection failed: ' + error.toString());
   remoting.LoadingWindow.close();
   remoting.MessageWindow.showErrorMessage(
       chrome.i18n.getMessage(/*i18n-content*/'CONNECTION_FAILED'),
       chrome.i18n.getMessage(error.getTag()));
 };
 
 /**
  * Close the loading window before exiting.
  */
 remoting.AppRemoting.prototype.handleExit = function() {
   remoting.LoadingWindow.close();
 };