Improve apps v2 upgrade UX

remoting/webapp/crd/js/remoting.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.
 
 'use strict';
 
 /** @suppress {duplicate} */
 var remoting = remoting || {};
 
 /**
  * @type {base.EventSource} An event source object for handling global events.
  *    This is an interim hack.  Eventually, we should move functionalities
  *    away from the remoting namespace and into smaller objects.
  */
 remoting.testEvents;
 
 /**
  * Initialization tasks that are common to all remoting apps.
  */
 remoting.initGlobalObjects = function() {
   if (base.isAppsV2()) {
     var htmlNode = /** @type {HTMLElement} */ (document.body.parentNode);
     htmlNode.classList.add('apps-v2');
-  } else {
-    migrateLocalToChromeStorage_();
   }
 
   console.log(remoting.getExtensionInfo());
   l10n.localize();
 
   if (base.isAppsV2()) {
     remoting.fullscreen = new remoting.FullscreenAppsV2();
   } else {
     remoting.fullscreen = new remoting.FullscreenAppsV1();
   }
@@ skipping 188 matching lines @@
       chrome.windows.get(tab.windowId, null, windowCallback);
     }
   };
   if (chrome.tabs) {
     chrome.tabs.getCurrent(tabCallback);
   } else {
     console.error('chome.tabs is not available.');
   }
 }
 
-/**
- * Migrate settings in window.localStorage to chrome.storage.local so that
- * users of older web-apps that used the former do not lose their settings.
- */
-function migrateLocalToChromeStorage_() {
-  // The OAuth2 class still uses window.localStorage, so don't migrate any of
-  // those settings.
-  var oauthSettings = [
-      'oauth2-refresh-token',
-      'oauth2-refresh-token-revokable',
-      'oauth2-access-token',
-      'oauth2-xsrf-token',
-      'remoting-email'
-  ];
-  for (var setting in window.localStorage) {
-    if (oauthSettings.indexOf(setting) == -1) {
-      var copy = {}
-      copy[setting] = window.localStorage.getItem(setting);
-      chrome.storage.local.set(copy);
-      window.localStorage.removeItem(setting);
-    }
-  }
-}