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

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

Index: chrome/browser/resources/demo_ui/events/events-demo.html
diff --git a/chrome/browser/resources/demo_ui/events/events-demo.html b/chrome/browser/resources/demo_ui/events/events-demo.html
new file mode 100644
index 0000000000000000000000000000000000000000..747567a47dcc20b9ab0951279386ccda579dc975
--- /dev/null
+++ b/chrome/browser/resources/demo_ui/events/events-demo.html
@@ -0,0 +1,15 @@
+<!-- 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/paper-button/paper-button.html">
+<link rel="import" href="../components/demo_ui/events/events-demo-view.html">
+
+<polymer-element name="events-demo" extends="events-demo-view" noscript>
+  <template>
+    <paper-button on-tap="{{fireEvent}}" event="buttonClicked">
+      Click me
+    </paper-button>
+    <div>Button clicked {{C.eventCounter}} times</div>
+  </template>
+</polymer-element>