If the dependency array is present, internal require('') calls do not trigger loading, they just get any cached module value, which may fail given that shared/js/l10n does not depend on l10n_date. I would just do:

```javascript
// l10n_date depends on shared/js/l10n so this all works out.
// By asking for l10n_date, we get the most inclusive dependency.
define(['shared/js/l10n_date'], function() {
  return navigator.mozL10n;
});
```