Validate map keys in C++ Mojo bindings

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

 {#- Validates the specified field, which is supposed to be an object
     (struct/array/string/map/union). If it is a union, |union_is_inlined|
     indicates whether the union is inlined. (Nested unions are not inlined.)
     This macro is expanded by the Validate() method. #}
 {%- macro validate_object(field, field_expr, object_name, union_is_inlined) %}
 {%-   set name = field.name %}
 {%-   set kind = field.kind %}
 {%-   if not kind|is_nullable_kind %}
 {%-     if kind|is_union_kind and union_is_inlined %}
   if (!mojo::internal::ValidateInlinedUnionNonNullable(
           {{field_expr}}, "null {{name}} field in {{object_name}}")) {
     return false;
   }
 {%-     else %}
   if (!mojo::internal::ValidatePointerNonNullable(
           {{field_expr}}, "null {{name}} field in {{object_name}}")) {
     return false;
   }
 {%-     endif %}
 {%-   endif %}
 {%-   if kind|is_array_kind or kind|is_string_kind %}
   const mojo::internal::ArrayValidateParams {{name}}_validate_params(
       {{kind|get_array_validate_params_ctor_args|indent(6)}});
   if (!mojo::internal::ValidateArray({{field_expr}}, bounds_checker,
                                      &{{name}}_validate_params)) {
     return false;
   }
 {%-   elif kind|is_map_kind %}
   const mojo::internal::ArrayValidateParams {{name}}_validate_params(
-      {{kind.value_kind|get_map_validate_params_ctor_args|indent(6)}});
+      {{kind|get_array_validate_params_ctor_args|indent(6)}});
   if (!mojo::internal::ValidateMap({{field_expr}}, bounds_checker,
                                    &{{name}}_validate_params)) {
     return false;
   }
 {%-   elif kind|is_struct_kind %}
   if (!mojo::internal::ValidateStruct({{field_expr}}, bounds_checker))
     return false;
 {%-   elif kind|is_union_kind %}
 {%-     if union_is_inlined %}
   if (!mojo::internal::ValidateInlinedUnion({{field_expr}}, bounds_checker))
@@ skipping 63 matching lines @@
 {%-   if field.kind|is_object_kind -%}
 {{validate_object(field, field_expr, object_name, union_is_inlined)}}
 {%-   elif field.kind|is_any_handle_kind or field.kind|is_interface_kind -%}
 {{validate_handle(field, field_expr, object_name)}}
 {%-   elif field.kind|is_associated_kind %}
 {{validate_associated(field, field_expr, object_name)}}
 {%-   elif field.kind|is_enum_kind %}
 {{validate_enum(field, field_expr)}}
 {%-   endif %}
 {%- endmacro %}