Delete MacVDA from the codebase since it is dead code and not being worked on.

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': [
     'shell_dialogs.gypi',
@@ skipping 527 matching lines @@
         'gfx/transform_util.cc',
         'gfx/transform_util.h',
         'gfx/vector2d.cc',
         'gfx/vector2d.h',
         'gfx/vector2d_conversions.cc',
         'gfx/vector2d_conversions.h',
         'gfx/vector2d_f.cc',
         'gfx/vector2d_f.h',
         'gfx/vector3d_f.cc',
         'gfx/vector3d_f.h',
-        'gfx/video_decode_acceleration_support_mac.h',
-        'gfx/video_decode_acceleration_support_mac.mm',
         'webui/jstemplate_builder.cc',
         'webui/jstemplate_builder.h',
         'webui/web_ui_util.cc',
         'webui/web_ui_util.h',
       ],
       'target_conditions': [
         ['OS == "ios"', {
           'sources/': [
             ['include', '^base/l10n/l10n_util_mac\\.mm$'],
           ],
@@ skipping 426 matching lines @@
               'xcode_settings': {
                 'GCC_SYMBOLS_PRIVATE_EXTERN': 'NO',
               },
             }],
           ],
         },
       ],
     }],
   ],
 }