MD Settings: Lazy-load sub-pages.

chrome/browser/resources/settings/settings_page/settings_subpage.js

-// Copyright 2015 The Chromium Authors. All rights reserved.
+// Copyright 2016 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.
 
 /**
  * @fileoverview
- * 'settings-subheader' shows a subheader for subpages. This header contains
+ * 'settings-subpage' shows a subpage beneath a subheader. The header contains
  * the subpage title and a back icon. The back icon fires an event which
  * is caught by settings-animated-pages, so it requires no separate handling.
- *
- * Examples:
- *
- *    <settings-subheader i18n-values="page-title:internetPageTitle">
- *    </settings-subheader>
  */
+
 Polymer({
-  is: 'settings-subheader',
+  is: 'settings-subpage',
+
+  behaviors: [
+    // TODO(michaelpg): phase out NeonAnimatableBehavior.
+    Polymer.NeonAnimatableBehavior,
+    Polymer.IronResizableBehavior,
+  ],
+
+  properties: {
+    pageTitle: String,
+  },
 
   /** @private */
   onTapBack_: function() {
     // Event is caught by settings-animated-pages.
     this.fire('subpage-back');
   },
 });