Use template specialization to generate WindowProperty code

ui/views/views.gyp

 # 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.
 {
   'variables': {
     'chromium_code': 1,
     # Sources lists shared with GN build.
     'views_sources': [
       'accessibility/native_view_accessibility.cc',
       'accessibility/native_view_accessibility.h',
@@ skipping 394 matching lines @@
       'widget/desktop_aura/desktop_drop_target_win.cc',
       'widget/desktop_aura/desktop_drop_target_win.h',
       'widget/desktop_aura/desktop_event_client.cc',
       'widget/desktop_aura/desktop_event_client.h',
       'widget/desktop_aura/desktop_focus_rules.cc',
       'widget/desktop_aura/desktop_focus_rules.h',
       'widget/desktop_aura/desktop_native_cursor_manager.cc',
       'widget/desktop_aura/desktop_native_cursor_manager.h',
       'widget/desktop_aura/desktop_native_widget_aura.cc',
       'widget/desktop_aura/desktop_native_widget_aura.h',
+      'widget/desktop_aura/desktop_native_widget_property.cc',
       'widget/desktop_aura/desktop_window_tree_host.h',
       'widget/desktop_aura/desktop_screen.h',
       'widget/desktop_aura/desktop_screen_position_client.cc',
       'widget/desktop_aura/desktop_screen_position_client.h',
     ],
     'views_desktop_aura_x11_sources': [
       'widget/desktop_aura/desktop_drag_drop_client_aurax11.cc',
       'widget/desktop_aura/desktop_drag_drop_client_aurax11.h',
       'widget/desktop_aura/desktop_window_tree_host_x11.cc',
       'widget/desktop_aura/desktop_window_tree_host_x11.h',
@@ skipping 465 matching lines @@
                 '../aura/aura.gyp:aura',
                 '../wm/wm.gyp:wm',
               ],
             }],
           ],
         },  # target_name: macviews_interactive_ui_tests
       ],  # targets
     }],
   ],  # conditions
 }