Add an experiment for the default browser infobar on Windows 10

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 1273 matching lines @@
       'browser/ui/cocoa/website_settings/split_block_button.mm',
       'browser/ui/cocoa/website_settings/website_settings_bubble_controller.h',
       'browser/ui/cocoa/website_settings/website_settings_bubble_controller.mm',
       'browser/ui/cocoa/website_settings/website_settings_utils_cocoa.h',
       'browser/ui/cocoa/website_settings/website_settings_utils_cocoa.mm',
       'browser/ui/cocoa/window_size_autosaver.h',
       'browser/ui/cocoa/window_size_autosaver.mm',
     ],
     # Files used only on desktop systems (not iOS, Android, ChromeOS).
     'chrome_browser_ui_desktop_sources': [
+      'browser/ui/startup/default_browser_infobar_delegate.cc',
+      'browser/ui/startup/default_browser_infobar_delegate.h',
       'browser/ui/startup/default_browser_prompt.cc',
       'browser/ui/startup/default_browser_prompt.h',
       'browser/ui/startup/default_browser_prompt_win.cc',
       'browser/ui/sync/one_click_signin_links_delegate.h',
       'browser/ui/sync/one_click_signin_links_delegate_impl.cc',
       'browser/ui/sync/one_click_signin_links_delegate_impl.h',
       'browser/ui/sync/one_click_signin_sync_observer.cc',
       'browser/ui/sync/one_click_signin_sync_observer.h',
       'browser/ui/sync/one_click_signin_sync_starter.cc',
       'browser/ui/sync/one_click_signin_sync_starter.h',
@@ skipping 1993 matching lines @@
           ],
           'sources': [
             '<@(chrome_browser_ui_non_mobile_sources)',
             '<@(chrome_browser_ui_omnibox_non_mobile_sources)',
           ],
         }],
       ],
     },
   ],
 }