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

chrome/browser/browser_resources.grd

Index: chrome/browser/browser_resources.grd
diff --git a/chrome/browser/browser_resources.grd b/chrome/browser/browser_resources.grd
index b0ce0fddc9e48a00a6db6aa01177300b611c86b6..699b2ac2172f3b4633eca54726a93b41516e1b28 100644
--- a/chrome/browser/browser_resources.grd
+++ b/chrome/browser/browser_resources.grd
@@ -440,6 +440,12 @@
       <include name="IDR_WHISPERNET_PROXY_MANIFEST" file="resources\whispernet_proxy\manifest.json" type="BINDATA" />
       <include name="IDR_MD_SETTINGS_UI_HTML" file="resources\md_settings\md_settings.html" type="BINDATA" />
       <include name="IDR_MD_SETTINGS_UI_CSS" file="resources\md_settings\md_settings.css" type="BINDATA" />
+      <include name="IDR_DEMO_UI_HTML" file="resources\demo_ui\demo_ui.html" type="chrome_html" />
+      <include name="IDR_DEMO_UI_DEMO_ELEMENT_HTML" file="resources\demo_ui\demo-element.html" type="chrome_html" />
+      <include name="IDR_DEMO_UI_DEMO_ELEMENT_JS" file="resources\demo_ui\demo-element.js" type="chrome_html" />
+      <include name="IDR_DEMO_UI_STRINGS_STRINGS_DEMO_HTML" file="resources\demo_ui\strings\strings-demo.html" type="chrome_html" />
+      <include name="IDR_DEMO_UI_EVENTS_EVENTS_DEMO_HTML" file="resources\demo_ui\events\events-demo.html" type="chrome_html" />
+      <include name="IDR_DEMO_UI_REUSE_REUSE_DEMO_HTML" file="resources\demo_ui\reuse\reuse-demo.html" type="chrome_html" />
     </includes>
   </release>
 </grit>