As per the previous commit, this is unnecessary.
Even with the small amount of css values we mark as is_computed, we
already skip computing over 60% of them like this during the startup of
the widget factory.
GtkCssStyle *style,
GtkCssStyle *parent_style)
{
+ if (gtk_css_value_is_computed (value))
+ return _gtk_css_value_ref (value);
+
return value->class->compute (value, property_id, provider, style, parent_style);
}