Generate subgroup StyleSurroundData in ComputedStyle.

third_party/WebKit/Source/build/scripts/templates/fields/base.tmpl

-{% from 'fields/field.tmpl' import encode, decode, return_type %}
+{% from 'fields/field.tmpl' import encode, decode, get_expr, set_expr, return_type %}
 {% macro decl_methods(field) -%}
-inline static {{return_type(field)}} {{field.initial_method_name}}() {
+inline static {{field.type_name}} {{field.initial_method_name}}() {
   return {{field.default_value}};
 }
 {{return_type(field)}} {{field.getter_method_name}}() const {
-  return {{decode(field, field.name)}};
+  return {{decode(field, get_expr(field))}};
 }
-void {{field.setter_method_name}}({{field.type_name}} v) {
-  {{field.name}} = {{encode(field, "v")}};
+void {{field.setter_method_name}}(const {{field.type_name}}& v) {
+  {{set_expr(field)}} = {{encode(field, "v")}};
 }
 inline void {{field.resetter_method_name}}() {
-  {{field.name}} = {{encode(field, field.default_value)}};
+  {{set_expr(field)}} = {{encode(field, field.default_value)}};
 }
 {%- endmacro %}