Polymer upgraded to 1.0 in login flow.

chrome/browser/resources/chromeos/login/html-echo.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.
 
-Polymer('html-echo', {
-  contentChanged: function() {
-    this.innerHTML = this.content;
+Polymer({
+  is: 'html-echo',
+
+  properties: {
+    content: {
+      type: String,
+      observer: 'contentChanged_'
+    }
+  },
+
+  contentChanged_: function(content) {
+    this.innerHTML = content;
   }
 });