The UI language rather than the locale is now used to pick Chrome's language ...

base/base.gypi

 # Copyright (c) 2010 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.
 
 {
   'target_defaults': {
     'variables': {
       'base_target': 0,
       'base_extra_target': 0,
     },
@@ skipping 273 matching lines @@
           'waitable_event.h',
           'waitable_event_posix.cc',
           'waitable_event_watcher.h',
           'waitable_event_watcher_posix.cc',
           'waitable_event_watcher_win.cc',
           'waitable_event_win.cc',
           'watchdog.cc',
           'watchdog.h',
           'weak_ptr.cc',
           'weak_ptr.h',
+          'win/i18n.cc',
+          'win/i18n.h',
           'win/pe_image.cc',
           'win/event_trace_consumer.h',
           'win/event_trace_controller.cc',
           'win/event_trace_controller.h',
           'win/event_trace_provider.cc',
           'win/event_trace_provider.h',
           'win/pe_image.h',
           'win/registry.cc',
           'win/registry.h',
           'win/scoped_bstr.cc',
@@ skipping 504 matching lines @@
             'third_party/xdg_mime/xdgmimemagic.c',
             'third_party/xdg_mime/xdgmimemagic.h',
             'third_party/xdg_mime/xdgmimeparent.c',
             'third_party/xdg_mime/xdgmimeparent.h',
           ],
         },
       ],
     }],
   ],
 }