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### Issue Details

* **Electron Version:**
  * 9.1.1
  * 10.0.0-beta.4
* **Operating System:**
  * Linux x64

### Expected Behavior

Don't crash when `nodeIntegrationInWorker` is `true` and a service worker is being registered. :slightly_smiling_face:

### Actual Behavior

A crash occurs once the service worker is attempted to be registered (blank page, DevTools disconnects).

### To Reproduce

Attempt to register a service worker with `nodeIntegrationInWorker` set to `true`.

```sh
$ git clone https://github.com/lgrahl/electron-node-integration-service-worker-crash
$ npm install
$ npm start
```

Commit https://github.com/lgrahl/electron-node-integration-service-worker-crash/commit/97b14f2c599bfd25ce416b8a7ee91d9122bbfe2c
shell/browser/electron_browser_client.cc
if (allowed) {
    platform_util::OpenExternal(
        escaped_url, platform_util::OpenExternalOptions(), base::DoNothing());
  }
}
void HandleExternalProtocolInUI(
    const GURL& url,
    content::WebContents::OnceGetter web_contents_getter,
    bool has_user_gesture) {
  content::WebContents* web_contents = std::move(web_contents_getter).Run();
  if (!web_contents)
    return;
  auto* permission_helper =
      WebContentsPermissionHelper::FromWebContents(web_contents);
  if (!permission_helper)
    return;
  GURL escaped_url(net::EscapeExternalHandlerValue(url.spec()));
  auto callback = base::BindOnce(&OnOpenExternal, escaped_url);
  permission_helper->RequestOpenExternalPermission(std::move(callback),
                                                   has_user_gesture, url);
}
bool ElectronBrowserClient::HandleExternalProtocol(