Force encryption migration if the device supports ARC.

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

 // Copyright 2017 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.
 
 login.createScreen('EncryptionMigrationScreen', 'encryption-migration',
     function() {
   return {
     EXTERNAL_API: [
       'setUIState',
       'setMigrationProgress',
     ],
 
     /**
      * Ignore any accelerators the user presses on this screen.
      */
     ignoreAccelerators: true,
 
     /** @override */
     decorate: function() {
       var encryptionMigration = $('encryption-migration-element');
       encryptionMigration.addEventListener('upgrade', function() {
         chrome.send('startMigration');
       });
+      encryptionMigration.addEventListener('skip', function() {
+        chrome.send('skipMigration');
+      });
       encryptionMigration.addEventListener('restart', function() {
         chrome.send('requestRestart');
       });
     },
 
     /**
      * Event handler that is invoked just before the screen in shown.
      */
     onBeforeShow: function() {
       $('progress-dots').hidden = true;
@@ skipping 15 matching lines @@
 
     /**
      * Updates the migration progress.
      * @param {number} progress The progress of migration in range [0, 1].
      */
     setMigrationProgress: function(progress) {
       $('encryption-migration-element').progress = progress;
     },
   };
 });