Added parseShorthand method from the parser to CSSPropertyAPI.h.

third_party/WebKit/Source/build/scripts/make_css_property_apis.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 sys
 
 import json5_generator
 import template_expander
 import make_style_builder
@@ skipping 42 matching lines @@
                 api_methods=api_methods_for_class[classname],
             ))
 
     @template_expander.use_jinja('CSSPropertyDescriptor.cpp.tmpl')
     def generate_property_descriptor_cpp(self):
         return {
             'api_classes': self._api_classes,
             'api_methods': self.json5_file.parameters['api_methods']['valid_values'],
         }
 
-    # Provides a function object given the classname of the property.
+    # This returned function generates a .h file for the specified property
     def generate_property_api_h_builder(self, api_classname, api_methods):
         @template_expander.use_jinja('CSSPropertyAPIFiles.h.tmpl')
         def generate_property_api_h():
             return {
                 'api_classname': api_classname,
                 'api_methods': api_methods,
             }
         return generate_property_api_h
 
 if __name__ == '__main__':
     json5_generator.Maker(CSSPropertyAPIWriter).main()