Adds View::GetNativeTheme() to get the NativeTheme. The interesting

ui/ui.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,
   },
   'includes': [
     'ui_resources.gypi',
@@ skipping 596 matching lines @@
             'base/cursor/cursor_win.cc',
             'base/cursor/cursor_x11.cc',
             'base/native_theme/native_theme_aura.cc',
             'base/native_theme/native_theme_aura.h',
           ]
         }],
         ['use_aura==1 and OS=="win"', {
           'sources/': [
             ['exclude', 'base/dragdrop/os_exchange_data_provider_win.cc'],
             ['exclude', 'base/dragdrop/os_exchange_data_provider_win.h'],
-            ['exclude', 'base/native_theme/native_theme_win.cc'],
-            ['exclude', 'base/native_theme/native_theme_win.h'],
           ],
         }],
         ['use_aura==0 and toolkit_views==0', {
           'sources/': [
             ['exclude', '^base/gestures/*'],
           ]
         }],
         ['use_aura==1 and use_ash==0 and OS=="linux"', {
           'sources': [
             'base/linux_ui.cc',
@@ skipping 260 matching lines @@
            },
            'dependencies': [
              '../base/base.gyp:base_java',
            ],
            'includes': [ '../build/java.gypi' ],
          },
        ],
     }],
   ],
 }