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

chrome/chrome_browser_ui.gypi

 # Copyright 2012 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.
 
 {
   'variables': {
     # There are two sections of sources:
     # * "Platform"-based sources (OS, toolkit, etc.)
     # * Feature/directory-based sources (e.g., history, printing)
 
@@ skipping 1014 matching lines @@
       'browser/ui/webui/constrained_web_dialog_delegate_base.cc',
       'browser/ui/webui/constrained_web_dialog_delegate_base.h',
       'browser/ui/webui/constrained_web_dialog_ui.cc',
       'browser/ui/webui/constrained_web_dialog_ui.h',
       'browser/ui/webui/cookies_tree_model_util.cc',
       'browser/ui/webui/cookies_tree_model_util.h',
       'browser/ui/webui/crashes_ui.cc',
       'browser/ui/webui/crashes_ui.h',
       'browser/ui/webui/device_log_ui.cc',
       'browser/ui/webui/device_log_ui.h',
+      'browser/ui/webui/demo_ui/demo.cc',
+      'browser/ui/webui/demo_ui/demo.h',
+      'browser/ui/webui/demo_ui/demo_ui.cc',
+      'browser/ui/webui/demo_ui/demo_ui.h',
+      'browser/ui/webui/demo_ui/events/events_demo.cc',
+      'browser/ui/webui/demo_ui/events/events_demo.h',
+      'browser/ui/webui/demo_ui/strings/strings_demo.cc',
+      'browser/ui/webui/demo_ui/strings/strings_demo.h',
+      'browser/ui/webui/demo_ui/reuse/reuse_demo.cc',
+      'browser/ui/webui/demo_ui/reuse/reuse_demo.h',
       'browser/ui/webui/domain_reliability_internals_ui.cc',
       'browser/ui/webui/domain_reliability_internals_ui.h',
       'browser/ui/webui/favicon_source.cc',
       'browser/ui/webui/favicon_source.h',
       'browser/ui/webui/fileicon_source.cc',
       'browser/ui/webui/fileicon_source.h',
       'browser/ui/webui/flags_ui.cc',
       'browser/ui/webui/flags_ui.h',
       'browser/ui/webui/gcm_internals_ui.cc',
       'browser/ui/webui/gcm_internals_ui.h',
@@ skipping 1678 matching lines @@
             '<@(chrome_browser_ui_toolbar_model_sources)',
             '<(SHARED_INTERMEDIATE_DIR)/chrome/browser/ui/webui/omnibox/omnibox.mojom.cc',
           ],
           'dependencies': [
             'chrome_web_ui_mojo_bindings.gyp:web_ui_mojo_bindings',
             'debugger',
             'installer_util',
             '../components/components.gyp:app_modal',
             '../components/components.gyp:autofill_content_risk_proto',
             '../components/components.gyp:translate_content_common',
+            '../components/components.gyp:demo_wug_generated',
+            '../components/components.gyp:events_demo_wug_generated',
+            '../components/components.gyp:reuse_demo_wug_generated',
+            '../components/components.gyp:strings_demo_wug_generated',
+            '../components/components.gyp:webui_generator',
             '../content/app/resources/content_resources.gyp:content_resources',
             '../media/media.gyp:media',
             '../net/net.gyp:net_with_v8',
             '../storage/storage_browser.gyp:storage',
             '../storage/storage_common.gyp:storage_common',
             '../third_party/expat/expat.gyp:expat',
             '../third_party/leveldatabase/leveldatabase.gyp:leveldatabase',
             '../third_party/libjingle/libjingle.gyp:libjingle',
             '../third_party/mojo/mojo_edk.gyp:mojo_system_impl',
             '../third_party/npapi/npapi.gyp:npapi',
@@ skipping 405 matching lines @@
           ],
           'sources': [
             '<@(chrome_browser_ui_non_mobile_sources)',
             '<@(chrome_browser_ui_omnibox_non_mobile_sources)',
           ],
         }],
       ],
     },
   ],
 }