Demo UI made with a help of WUG toolkit (DO NOT SEND TO CQ).

chrome/browser/resources/demo_ui/demo-element.html

Index: chrome/browser/resources/demo_ui/demo-element.html
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+<!-- Copyright 2015 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. -->
+
+<link rel="import" href="chrome://resources/polymer/core-animated-pages/core-animated-pages.html">
+<link rel="import" href="chrome://resources/polymer/core-animated-pages/transitions/slide-from-right.html">
+<link rel="import" href="chrome://resources/polymer/paper-tabs/paper-tabs.html">
+<link rel="import" href="components/demo_ui/demo-view.html">
+<link rel="import" href="events/events-demo.html">
+<link rel="import" href="reuse/reuse-demo.html">
+<link rel="import" href="strings/strings-demo.html">
+
+<polymer-element name="demo-element" extends="demo-view">
+  <template>
+    <style>
+      paper-tabs {
+        background-color: #00bcd4;
+        color: #fff;
+        box-shadow: 0px 3px 2px rgba(0, 0, 0, 0.2);
+        text-transform: uppercase;
+        font-weight: bold;
+      }
+    </style>
+    <template repeat="{{ kv in contextDump }}">
+      <div>{{kv.key}}: '{{kv.value}}'</div>
+    </template>
+    <paper-tabs selected="{{selectedPage}}" noink>
+      <paper-tab>Events demo</paper-tab>
+      <paper-tab>Strings demo</paper-tab>
+      <paper-tab>Reuse demo</paper-tab>
+    </paper-tabs>
+    <core-animated-pages selected="{{selectedPage}}" transitions="slide-from-right">
+      <events-demo wugid="events"></events-demo>
+      <strings-demo wugid="strings"></strings-demo>
+      <reuse-demo wugid="reuse"></reuse-demo>
+    </core-animated-pages>
+  </template>
+</polymer-element>
+
+<script src="demo-element.js"></script>