WebUI: Fix violations of no-extra-semi lint rule.

ui/webui/resources/js/cr/ui/alert_overlay.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.
 
 cr.define('alertOverlay', function() {
   /**
    * The confirm <button>.
    * @type {HTMLElement}
    */
   var okButton;
@@ skipping 17 matching lines @@
       okButton.clickCallback = null;
       cancelButton.clickCallback = null;
     });
     cancelButton.addEventListener('click', function(e) {
       assert(cancelButton.clickCallback);
 
       cancelButton.clickCallback(e);
       okButton.clickCallback = null;
       cancelButton.clickCallback = null;
     });
-  };
+  }
 
   /**
    * Updates the alert overlay with the given message, button titles, and
    * callbacks.
    * @param {string} title The alert title to display to the user.
    * @param {string} message The alert message to display to the user.
    * @param {string=} opt_okTitle The title of the OK button. If undefined or
    *     empty, no button is shown.
    * @param {string=} opt_cancelTitle The title of the cancel button. If
    *     undefined or empty, no button is shown.
@@ skipping 16 matching lines @@
 
     if (opt_okTitle)
       okButton.textContent = opt_okTitle;
     okButton.hidden = !opt_okTitle;
     okButton.clickCallback = opt_okCallback;
 
     if (opt_cancelTitle)
       cancelButton.textContent = opt_cancelTitle;
     cancelButton.hidden = !opt_cancelTitle;
     cancelButton.clickCallback = opt_cancelCallback;
-  };
+  }
 
   // Export
   return {initialize: initialize, setValues: setValues};
 });
 
 document.addEventListener('DOMContentLoaded', alertOverlay.initialize);