Generate subgroup StyleSurroundData in ComputedStyle.

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

 {% macro encode(field, value) %}
 {% if field.is_bit_field -%}
 static_cast<unsigned>({{value}})
 {%- else -%}
 {{value}}
 {%- endif %}
 {% endmacro %}
 
 {% macro decode(field, value) %}
 {% if field.is_bit_field -%}
 static_cast<{{field.type_name}}>({{value}})
 {%- else -%}
 {{value}}
 {%- endif %}
 {% endmacro %}
 
+{% macro get_expr(field) %}

[meade_UTC10, 2017/04/06 03:29:57]

Can we name this better (and use full words)? e.g. 

field_getter(field)
getter_expression(field)

[shend, 2017/04/06 04:39:40]

For these macros, should the naming be treated as if they were methods of field
(e.g. field.getter_expression) or as if they were free functions
(field_getter_expression)? Technically callers can use both notations (the
latter being slightly more verbose), but I would like to be consistent.

[meade_UTC10, 2017/04/20 03:08:40]

I don't have strong opinions, other than consistency, and using the one that is
the clearest about what's going on. I guess field.getter_expression is the way
to go :)

[shend, 2017/04/20 03:22:34]

Ok, I did getter_expression(field), since field.getter_expression(field) is
repetitive.

+{% if field.field_group -%}
+m_{{field.field_group}}->{{field.name}}
+{%- else -%}
+{{field.name}}
+{%- endif %}
+{% endmacro %}
+
+{% macro set_expr(field) %}

[meade_UTC10, 2017/04/06 03:29:57]

ditto

[shend, 2017/04/20 03:22:34]

Done.

+{% if field.field_group -%}
+m_{{field.field_group}}.access()->{{field.name}}
+{%- else -%}
+{{field.name}}
+{%- endif %}
+{% endmacro %}
+
 {% macro return_type(field) %}
 {% if field.is_bit_field -%}
 {{field.type_name}}
 {%- else -%}
 const {{field.type_name}}&
 {%- endif %}
 {% endmacro %}