Add a basic stub Polymer settings page at chrome://md-settings.

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 1624 matching lines @@
       'browser/ui/webui/help/version_updater.h',
       'browser/ui/webui/help/version_updater_chromeos.cc',
       'browser/ui/webui/help/version_updater_chromeos.h',
       'browser/ui/webui/help/version_updater_mac.h',
       'browser/ui/webui/help/version_updater_mac.mm',
       'browser/ui/webui/help/version_updater_win.cc',
       'browser/ui/webui/identity_internals_ui.cc',
       'browser/ui/webui/identity_internals_ui.h',
       'browser/ui/webui/inspect_ui.cc',
       'browser/ui/webui/inspect_ui.h',
+      'browser/ui/webui/md_settings_ui.cc',
+      'browser/ui/webui/md_settings_ui.h',
       'browser/ui/webui/ntp/app_launcher_handler.cc',
       'browser/ui/webui/ntp/app_launcher_handler.h',
       'browser/ui/webui/ntp/app_resource_cache_factory.cc',
       'browser/ui/webui/ntp/app_resource_cache_factory.h',
       'browser/ui/webui/ntp/core_app_launcher_handler.cc',
       'browser/ui/webui/ntp/core_app_launcher_handler.h',
       'browser/ui/webui/ntp/favicon_webui_handler.cc',
       'browser/ui/webui/ntp/favicon_webui_handler.h',
       'browser/ui/webui/ntp/foreign_session_handler.cc',
       'browser/ui/webui/ntp/foreign_session_handler.h',
@@ skipping 1473 matching lines @@
           ],
           'sources': [
             '<@(chrome_browser_ui_non_mobile_sources)',
             '<@(chrome_browser_ui_omnibox_non_mobile_sources)',
           ],
         }],
       ],
     },
   ],
 }