Add Mac10.12 to the configuration tokens list.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/models/test_expectations.py

 # Copyright (C) 2010 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 261 matching lines @@
         return len(self.parsed_expectations) > 1
 
     def is_comment(self):
         return bool(re.match(r"^\s*#.*$", self.original_string))
 
     def is_whitespace(self):
         return not self.original_string.strip()
 
     # FIXME: Update the original specifiers and remove this once the old syntax is gone.
     _configuration_tokens_list = [
-        'Mac', 'Mac10.9', 'Mac10.10', 'Mac10.11', 'Retina',
+        'Mac', 'Mac10.9', 'Mac10.10', 'Mac10.11', 'Retina', 'Mac10.12',
         'Win', 'Win7', 'Win10',
         'Linux', 'Trusty',
         'Android',
         'Release',
         'Debug',
     ]
 
     _configuration_tokens = dict((token, token.upper()) for token in _configuration_tokens_list)
     _inverted_configuration_tokens = dict((value, name) for name, value in _configuration_tokens.iteritems())
 
@@ skipping 918 matching lines @@
             # If reconstitute_only_these is an empty list, we want to return original_string.
             # So we need to compare reconstitute_only_these to None, not just check if it's falsey.
             if reconstitute_only_these is None or expectation_line in reconstitute_only_these:
                 return expectation_line.to_string(test_configuration_converter)
             return expectation_line.original_string
 
         def nones_out(expectation_line):
             return expectation_line is not None
 
         return '\n'.join(filter(nones_out, map(serialize, expectation_lines)))