[Chromecast] Remove libffmpegsumo dummy

chromecast/media/media.gyp

 # Copyright 2014 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,
     'chromecast_branding%': 'public',
   },
   'target_defaults': {
     'include_dirs': [
       '../..',  # Root of Chromium checkout
       '../public/',  # Public APIs
     ],
   },
   'targets': [
-    # TODO(slan): delete this target once Chromecast M44/earlier is obsolete.
-    # See: b/21639416
-    {
-      'target_name': 'libffmpegsumo',
-      'type': 'loadable_module',
-      'sources': ['empty.cc'],
-    },
     {
       'target_name': 'media_audio',
       'type': '<(component)',
       'dependencies': [
         '../../media/media.gyp:media',
       ],
       'sources': [
         'audio/cast_audio_manager.cc',
         'audio/cast_audio_manager.h',
         'audio/cast_audio_manager_factory.cc',
@@ skipping 290 matching lines @@
       'dependencies': [
         '../../chromecast/chromecast.gyp:cast_public_api',
         'default_cma_backend'
       ],
       'sources': [
         'base/cast_media_default.cc',
       ],
     },
   ], # end of targets
 }