Fixed the racy code around the message-only window in base::MessagePumpForUI on Windows.

base/base.gypi

 # Copyright (c) 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.
 
 {
   'target_defaults': {
     'variables': {
       'base_target': 0,
     },
     'target_conditions': [
@@ skipping 535 matching lines @@
           'value_conversions.cc',
           'value_conversions.h',
           'version.cc',
           'version.h',
           'vlog.cc',
           'vlog.h',
           'nix/mime_util_xdg.cc',
           'nix/mime_util_xdg.h',
           'nix/xdg_util.cc',
           'nix/xdg_util.h',
+          'win/enum_variant.cc',
           'win/enum_variant.h',
-          'win/enum_variant.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/i18n.cc',
           'win/i18n.h',
           'win/iat_patch_function.cc',
           'win/iat_patch_function.h',
+          'win/iunknown_impl.cc',
           'win/iunknown_impl.h',
-          'win/iunknown_impl.cc',
+          'win/message_window.cc',
+          'win/message_window.h',
           'win/metro.cc',
           'win/metro.h',
           'win/object_watcher.cc',
           'win/object_watcher.h',
           'win/registry.cc',
           'win/registry.h',
           'win/resource_util.cc',
           'win/resource_util.h',
           'win/sampling_profiler.cc',
           'win/sampling_profiler.h',
@@ skipping 12 matching lines @@
           'win/scoped_propvariant.h',
           'win/scoped_select_object.h',
           'win/scoped_variant.cc',
           'win/scoped_variant.h',
           'win/shortcut.cc',
           'win/shortcut.h',
           'win/startup_information.cc',
           'win/startup_information.h',
           'win/text_services_message_filter.cc',
           'win/text_services_message_filter.h',
+          'win/win_util.cc',
+          'win/win_util.h',
           'win/windows_version.cc',
           'win/windows_version.h',
-          'win/win_util.cc',
-          'win/win_util.h',
           'win/wrapped_window_proc.cc',
           'win/wrapped_window_proc.h',
         ],
         'conditions': [
           ['google_tv==1', {
            'sources': [
              'android/context_types.cc',
              'android/context_types.h',
            ],
           }],
@@ skipping 204 matching lines @@
           ['<(use_system_nspr)==1 and >(nacl_untrusted_build)==0', {
             'sources/': [
               ['exclude', '^third_party/nspr/'],
             ],
           }],
         ],
       }],
     ],
   },
 }