Filter out shorthands for make_computed_style_base.py.

third_party/WebKit/Source/build/scripts/make_computed_style_base.py

 #!/usr/bin/env python
 # Copyright 2016 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.
 
 import math
 import sys
 
 import json5_generator
 import template_expander
@@ skipping 299 matching lines @@
 
         # TODO(shend): Remove this once we move NONPROPERTIES to its own JSON file,
         # since the JSON5 reader will handle missing fields and defaults.
         for property_ in NONPROPERTIES:
             property_['name_for_methods'] = property_['name']
             if 'field_type_path' not in property_:
                 property_['field_type_path'] = None
             if 'type_name' not in property_:
                 property_['type_name'] = 'E' + enum_type_name(property_['name_for_methods'])
 
-        property_values = self._properties.values()
+        # Ignore shorthand properties
+        for property_ in self._properties.values():
+            if property_['field_template'] is not None:
+                assert not property_['longhands'], \
+                    "Shorthand '{}' cannot have a field_template.".format(property_['name'])
+
+        property_values = [value for value in self._properties.values() if not value['longhands']]
 
         for property_ in property_values:
             # Override the type name when field_type_path is specified
             if property_['field_type_path']:
                 property_['type_name'] = property_['field_type_path'].split('/')[-1]
             # CSS properties are not allowed to explicitly specify their field_size.
             property_['field_size'] = None
 
         self._generated_enums = _create_enums(property_values + NONPROPERTIES)
 
@@ skipping 75 matching lines @@
                     'mapping': [(enum_value_name(k), enum_for_css_keyword(k)) for k in property_['keywords']],
                 }
 
         return {
             'include_paths': self._include_paths,
             'mappings': mappings,
         }
 
 if __name__ == '__main__':
     json5_generator.Maker(ComputedStyleBaseWriter).main()