### Preflight Checklist

- [x] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/master/CONTRIBUTING.md) for this project.
- [X] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/master/CODE_OF_CONDUCT.md) that this project adheres to.
- [X] I have searched the [issue tracker](https://www.github.com/electron/electron/issues) for a feature request that matches the one I want to file, without success.

### Electron Version

15.0.0-alpha.10

### What operating system are you using?

macOS

### Operating System Version

macOS Big Sur 11.5.2

### What arch are you using?

x64

### Last Known Working Electron version

This feature never worked before

### Expected Behavior

`navigator.fonts.query()` should return a promise which in turn should resolve with a list of fonts provided by the operating system.

### Actual Behavior

`navigator.fonts.query()` causes the renderer process to crash (the window becomes gray and the dev tools are disconnected).

### Testcase Gist URL

_No response_

### Additional Information

`navigator.fonts.query()` is part of the experimental [Local Font Access API](https://www.chromestatus.com/feature/6234451761692672) and it must be first enabled by adding `FontAccess` to `webPreferences.enableBlinkFeatures`.

I was also able to reproduce this bug with Electron 13.2.3. I was unable to reproduce it with Chrome 92.
shell/browser/electron_browser_client.cc
ElectronBrowserClient::GetPluginMimeTypesWithExternalHandlers(
    content::BrowserContext* browser_context) {
  base::flat_set<std::string> mime_types;
#if BUILDFLAG(ENABLE_PLUGINS) && BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
  auto map = PluginUtils::GetMimeTypeToExtensionIdMap(browser_context);
  for (const auto& pair : map)
    mime_types.insert(pair.first);
#endif
  return mime_types;
}
content::SerialDelegate* ElectronBrowserClient::GetSerialDelegate() {
  if (!serial_delegate_)
    serial_delegate_ = std::make_unique<ElectronSerialDelegate>();
  return serial_delegate_.get();
}
content::BluetoothDelegate* ElectronBrowserClient::GetBluetoothDelegate() {