Change name of NativeTheme::instance() to make it clear it's web only.

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 822 matching lines @@
         '../accessibility/accessibility.gyp:accessibility',
         '../base/ime/ui_base_ime.gyp:ui_base_ime',
         '../base/ui_base.gyp:ui_base',
         '../base/ui_base.gyp:ui_base_test_support',
         '../compositor/compositor.gyp:compositor',
         '../events/events.gyp:events',
         '../events/events.gyp:events_base',
         '../events/events.gyp:events_test_support',
         '../gfx/gfx.gyp:gfx',
         '../gfx/gfx.gyp:gfx_geometry',
+        '../native_theme/native_theme.gyp:native_theme',
         '../resources/ui_resources.gyp:ui_resources',
         '../resources/ui_resources.gyp:ui_test_pak',
         '../strings/ui_strings.gyp:ui_strings',
         'resources/views_resources.gyp:views_resources',
         'views',
         'views_test_support',
       ],
       'include_dirs': [
         '..',
       ],
@@ skipping 112 matching lines @@
                 '../aura/aura.gyp:aura',
                 '../wm/wm.gyp:wm',
               ],
             }],
           ],
         },  # target_name: macviews_interactive_ui_tests
       ],  # targets
     }],
   ],  # conditions
 }