Bugzilla

The fuzzer is using a [testing-only method here that it should not be using](https://searchfox.org/mozilla-central/rev/55837bbe3e47f9b4fa91ef83a44b53823626f01d/dom/webidl/ServiceWorkerContainer.webidl#38-42):
```
// Testing only.
partial interface ServiceWorkerContainer {
  [Throws,Pref="dom.serviceWorkers.testing.enabled"]
  DOMString getScopeForUrl(DOMString url);
};
```

The fuzzer is using a [testing-only method here that it should not be using](https://searchfox.org/mozilla-central/rev/55837bbe3e47f9b4fa91ef83a44b53823626f01d/dom/webidl/ServiceWorkerContainer.webidl#38-42):
```
// Testing only.
partial interface ServiceWorkerContainer {
  [Throws,Pref="dom.serviceWorkers.testing.enabled"]
  DOMString getScopeForUrl(DOMString url);
};
```

This is the SW script:
```js
(async () => {
    await self.navigator.storage.getDirectory()
    self.navigator.serviceWorker.getScopeForUrl("missing.js")
    self.addEventListener("fetch", async () => {}, { })
})()
```