Make aura_demo work on Mac

ui/ui_unittests.gyp

 # Copyright 2013 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,
   },
   'targets': [
     {
@@ skipping 36 matching lines @@
           'sources/': [['exclude', 'cocoa']],
         }],
         ['chromeos==1', {
           'dependencies': [
             '../chromeos/chromeos.gyp:chromeos_test_support_without_gmock',
             '../skia/skia.gyp:skia',
           ],
         }],
         ['use_aura==1', {
           'sources!': [
+            'base/test/ui_controls_mac.mm',
             'base/test/ui_controls_win.cc',
           ],
         }],
       ],
     },
     {
       'target_name': 'run_ui_unittests',
       'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
@@ skipping 295 matching lines @@
           'variables': {
             'test_suite_name': 'ui_unittests',
             'input_shlib_path': '<(SHARED_LIB_DIR)/<(SHARED_LIB_PREFIX)ui_unittests<(SHARED_LIB_SUFFIX)',
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
       ],
     }],
   ],
 }