Add demo_page.html to cr_elements/v0_8

ui/webui/resources/cr_elements/v0_8/demo_element.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.
+
+/**
+ * @fileoverview Polymer element for UI wrapping a list of cr- elements.
+ */
+Polymer({
+  is: 'cr-demo-element',
+
+  properties: {
+    checkboxChecked: {
+      type: Boolean,
+      value: true,
+      observer: 'checkboxCheckedChanged_'
+    },
+
+    collapseOpened: {
+      type: Boolean,
+      value: true,
+      observer: 'collapseOpenedChanged_'
+    },
+
+    inputValue: {
+      type: String,
+      value: '',
+      observer: 'inputValueChanged_'
+    },
+  },
+
+  checkboxCheckedChanged_: function() {
+    console.log('checkboxCheckedChanged=' + this.checkboxChecked);
+  },
+
+  collapseOpenedChanged_: function() {
+    console.log('collapseOpened=' + this.collapseOpened);
+  },
+
+  inputValueChanged_: function() {
+    console.log('inputValue=' + this.inputValue);
+  }
+});