Rename "test" ozone platform to "headless"

chromecast/chromecast_tests.gypi

 # Copyright (c) 2014 Google Inc. 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 369 matching lines @@
         # GN target: //chromecast:cast_test_lists
         {
           'target_name': 'cast_test_lists',
           'type': 'none',
           'dependencies': [
             'cast_tests',
           ],
           'variables': {
             'test_generator_py': '<(DEPTH)/chromecast/tools/build/generate_test_lists.py',
             'test_inputs_dir': '<(SHARED_INTERMEDIATE_DIR)/chromecast/tests',
-            'test_additional_options': '--ozone-platform=test'
+            'test_additional_options': '--ozone-platform=headless'
           },
           'actions': [
             {
               'action_name': 'generate_combined_test_build_list',
               'message': 'Generating combined test build list',
               'inputs': ['<(test_generator_py)'],
               'outputs': ['<(PRODUCT_DIR)/tests/build_test_list.txt'],
               'action': [
                 'python', '<(test_generator_py)',
                 '-t', '<(test_inputs_dir)',
@@ skipping 13 matching lines @@
                 '-a', '<(test_additional_options)',
                 'pack_run',
               ],
             }
           ],
         },
       ],  # end of targets
     }],
   ],  # end of conditions
 }