Merge CSSPropertyNames.in and SVGCSSPropertyNames.in with CSSProperties.in

Source/build/scripts/css_properties.py

 #!/usr/bin/env python
 # 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.
 
 import in_generator
 from name_utilities import lower_first
 
 
 class CSSProperties(in_generator.Writer):
     defaults = {
+        'alias_for': None,
         'longhands': '',
         'font': False,
         'svg': False,
         'name_for_methods': None,
         'use_handlers_for': None,
         'getter': None,
         'setter': None,
         'initial': None,
         'type_name': None,
         'converter': None,
@@ skipping 14 matching lines @@
         'custom_value': (True, False),
         'builder_skip': (True, False),
         'direction_aware': (True, False),
     }
 
     def __init__(self, file_paths):
         in_generator.Writer.__init__(self, file_paths)
 
         properties = self.in_file.name_dictionaries
 
-        for property in properties:
+        self._aliases = {property['name']: property['alias_for'] for property in properties if property['alias_for']}
+        properties = [property for property in properties if not property['alias_for']]
+
+        assert len(properties) <= 1024, 'There are more than 1024 CSS Properties, you need to update CSSProperty.h/StylePropertyMetadata m_propertyID accordingly.'
+        # We currently assign 0 to CSSPropertyInvalid
+        self._first_enum_value = 1
+        for offset, property in enumerate(properties):
             property['property_id'] = css_name_to_enum(property['name'])
             property['upper_camel_name'] = camelcase_css_name(property['name'])
             property['lower_camel_name'] = lower_first(property['upper_camel_name'])
+            property['enum_value'] = self._first_enum_value + offset
+            property['is_internal'] = property['name'].startswith('-internal-')
 
         self._properties_list = properties
         self._properties = {property['property_id']: property for property in properties}
 
 
 def camelcase_css_name(css_name):
     """Convert hyphen-separated-name to UpperCamelCase.
 
     E.g., '-foo-bar' becomes 'FooBar'.
     """
     return ''.join(word.capitalize() for word in css_name.split('-'))
 
 
 def css_name_to_enum(css_name):
     return 'CSSProperty' + camelcase_css_name(css_name)