Actual cancelation of registration when cancel buttons pressed

chrome/browser/resources/local_discovery/local_discovery.js

 // Copyright 2013 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.
 
 /**
  * Javascript for local_discovery.html, served from chrome://devices/
  * This is used to show discoverable devices near the user.
  *
  * The simple object defined in this javascript file listens for
  * callbacks from the C++ code saying that a new device is available.
@@ skipping 126 matching lines @@
     uber.invokeMethodOnParent('beginInterceptingEvents');
   }
 
   /**
    * Show the register overlay.
    */
   function hideRegisterOverlay() {
     $('register-overlay').classList.remove('showing');
     $('overlay').hidden = true;
     uber.invokeMethodOnParent('stopInterceptingEvents');
+    chrome.send('cancelRegistration');
   }
 
   /**
    * Clear a DOM element of all children.
    * @param {HTMLElement} element DOM element to clear.
    */
   function clearElement(element) {
     while (element.firstChild) {
       element.removeChild(element.firstChild);
     }
@@ skipping 114 matching lines @@
   });
 
   return {
     registrationSuccess: registrationSuccess,
     registrationFailed: registrationFailed,
     onDeviceUpdate: onDeviceUpdate,
     requestUser: requestUser,
     registrationConfirmedOnPrinter: registrationConfirmedOnPrinter
   };
 });