Make the fuchsia mojo/public repo the source of truth.

mojo/public/tools/bindings/generators/js_templates/enum_definition.tmpl

-{%- macro enum_def(enum_name, enum) -%}
-  {{enum_name}} = {};
-{%- set prev_enum = 0 %}
-{%- for field in enum.fields %}
-{%-   if field.value %}
-  {{enum_name}}.{{field.name}} = {{field.value|expression_to_text}};
-{%-   elif loop.first %}
-  {{enum_name}}.{{field.name}} = 0;
-{%-   else %}
-  {{enum_name}}.{{field.name}} = {{enum_name}}.{{enum.fields[loop.index0 - 1].name}} + 1;
-{%-   endif %}
-{%- endfor %}
-{%- endmacro %}