Add 'storage_only' template to 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
 import make_style_builder
 
 from name_utilities import camel_case, lower_first, upper_first_letter, enum_for_css_keyword
 
 
 # Temporary hard-coded list of fields that are not CSS properties.
 # Ideally these would be specified in a .json5 file.
 NONPROPERTY_FIELDS = [
     {'name': 'isLink', 'field_template': 'monotonic_flag'},
     # Style can not be shared.
     {'name': 'unique', 'field_template': 'monotonic_flag'},
     # Whether this style is affected by these pseudo-classes.
     {'name': 'affectedByFocus', 'field_template': 'monotonic_flag'},
     {'name': 'affectedByHover', 'field_template': 'monotonic_flag'},
     {'name': 'affectedByActive', 'field_template': 'monotonic_flag'},
     {'name': 'affectedByDrag', 'field_template': 'monotonic_flag'},
     # A non-inherited property references a variable or @apply is used
     {'name': 'hasVariableReferenceFromNonInheritedProperty', 'field_template': 'monotonic_flag'},
     # Explicitly inherits a non-inherited property
-    {'name': 'hasExplicitlyInheritedProperties', 'field_template': 'monotonic_flag'}
+    {'name': 'hasExplicitlyInheritedProperties', 'field_template': 'monotonic_flag'},
+    # These properties only have generated storage, and their methods are handwritten in ComputedStyle.
+    # TODO(shend): Remove these fields and delete the 'storage_only' template.
+    {'name': 'emptyState', 'field_template': 'storage_only', 'size': 1}
 ]
 
 
 class Field(object):
     """
     The generated ComputedStyle object is made up of a series of Fields.
     Each Field has a name, size, type, etc, and a bunch of attributes to
     determine which methods it will be used in.
 
     A Field also has enough information to use any storage type in C++, such as
@@ skipping 158 matching lines @@
         initial_method_name='initial' + field_name_suffix_upper,
         resetter_method_name='reset' + field_name_suffix_upper,
     )
 
 
 def _create_nonproperty_field(property_):
     """
     Create a nonproperty field from an entry in NONPROPERTY_FIELDS and return the Field object.
     """
     # TODO(shend): Make this work for nonflags
-    assert property_['field_template'] in ('flag', 'monotonic_flag'), \
+    assert property_['field_template'] in ('flag', 'monotonic_flag', 'storage_only'), \
         "Nonproperties with arbitrary templates are not yet supported"
     member_name = 'm_' + property_['name']
     field_name_upper = upper_first_letter(property_['name'])
 
+    if property_['field_template'] == 'storage_only':
+        assert 'size' in property_, 'storage_only fields need to specify a size'
+        size = property_['size']
+    else:
+        # Otherwise the field must be some type of flag.
+        size = 1
+
     return Field(
         'nonproperty',
         name=member_name,
         property_name=property_['name'],
         type_name='bool',
         field_template=property_['field_template'],
-        size=1,
+        size=size,
         default_value='false',
         getter_method_name=property_['name'],
         setter_method_name='set' + field_name_upper,
         initial_method_name='initial' + field_name_upper,
         resetter_method_name='reset' + field_name_upper,
     )
 
 
 def _create_fields(properties):
     """
@@ skipping 145 matching lines @@
                     'mapping': [('k' + camel_case(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()