Adding the chrome://copresence page

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': {
     'chrome_browser_ui_non_ios_sources': [
       'browser/ui/accelerator_utils.h',
       'browser/ui/android/android_about_app_info.cc',
       'browser/ui/android/android_about_app_info.h',
@@ skipping 1789 matching lines @@
     'chrome_browser_ui_non_mobile_sources': [
       'browser/ui/browser_commands.cc',
       'browser/ui/browser_commands.h',
       'browser/ui/browser_tab_restorer.cc',
       'browser/ui/browser_window_state.cc',
       'browser/ui/browser_window_state.h',
       'browser/ui/scoped_tabbed_browser_displayer.cc',
       'browser/ui/scoped_tabbed_browser_displayer.h',
       'browser/ui/sync/sync_promo_ui.cc',
       'browser/ui/sync/sync_promo_ui.h',
+      'browser/ui/webui/copresence_ui_handler.cc',
+      'browser/ui/webui/copresence_ui_handler.h',
+      'browser/ui/webui/copresence_ui.cc',
+      'browser/ui/webui/copresence_ui.h',
       'browser/ui/webui/devtools_ui.cc',
       'browser/ui/webui/devtools_ui.h',
     ],
     'chrome_browser_ui_print_preview_sources': [
       'browser/ui/webui/print_preview/print_preview_handler.cc',
       'browser/ui/webui/print_preview/print_preview_handler.h',
       'browser/ui/webui/print_preview/print_preview_ui.cc',
       'browser/ui/webui/print_preview/print_preview_ui.h',
       'browser/ui/webui/print_preview/sticky_settings.cc',
       'browser/ui/webui/print_preview/sticky_settings.h',
@@ skipping 1265 matching lines @@
         }],
         ['enable_extensions==1', {
           'dependencies': [
             '<(DEPTH)/extensions/components/extensions_components.gyp:javascript_dialog_extensions_client',
           ],
         }],
         ['OS=="win" and (chromium_win_pch==0 or syzyasan==1)', {
           'msvs_shard': 4,
         }],
         ['OS!="android" and OS!="ios"', {
+          'sources': [ '<@(chrome_browser_ui_non_mobile_sources)' ],
           'dependencies': [
             '../device/bluetooth/bluetooth.gyp:device_bluetooth',
           ],
           'sources': [ '<@(chrome_browser_ui_non_mobile_sources)' ],
         }],
       ],
     },
   ],
 }