Mojo bindings: Fix typemap includes.

mojo/public/tools/bindings/generators/cpp_templates/struct_serialization_definition.tmpl

 {%- import "struct_macros.tmpl" as struct_macros %}
 size_t GetSerializedSize_(const {{struct.name}}Ptr& input,
                           mojo::internal::SerializationContext* context) {
   if (!input)
     return 0;
   {{struct_macros.get_serialized_size(struct, "input->%s", "context")}}
   return size;
 }
 
 void Serialize_({{struct.name}}Ptr input, mojo::internal::Buffer* buf,
@@ skipping 14 matching lines @@
   if (input) {
     {{struct.name}}Ptr result({{struct.name}}::New());
     {{struct_macros.deserialize(struct, "input", "result->%s", "context", "success")|indent(2)}}
     *output = std::move(result);
   } else {
     output->reset();
   }
   return success;
 }
 
-{%- if not variant and not struct|is_native_only_kind %}
+{%- if not struct|is_native_only_kind %}
 
 {{struct.name}}_Reader::{{struct.name}}_Reader(
     internal::{{struct.name}}_Data*  data,
     mojo::internal::SerializationContext* context)
     : data_(data), context_(context) { }
 
 {%- for pf in struct.packed.packed_fields_in_ordinal_order %}
 {%-   set name = pf.field.name -%}
 {%-   set kind = pf.field.kind %}
 {%-   if kind|is_nullable_kind %}
@@ skipping 24 matching lines @@
 {%-   elif kind|is_string_kind %}
 base::StringPiece {{struct.name}}_Reader::{{name}}() const {
   DCHECK(data_->{{name}}.ptr);
   return base::StringPiece(data_->{{name}}.ptr->storage(),
                            data_->{{name}}.ptr->size());
 }
 {%-   endif %}
 {%- endfor %}
 
 {%- endif %}