### 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

14.0.0 beta 9

### What operating system are you using?

macOS

### Operating System Version

macOS Catalina 10.15.7

### What arch are you using?

x64

### Last Known Working Electron version

14.0.0 beta 8

### Expected Behavior

`console.log(app.getPath('userData'))` in main.js in Fiddle should output something like `/Users/miburda/Library/Application Support/stereotyped-rub-drain-i2tik`

### Actual Behavior

`console.log(app.getPath('userData'))` in main.js in Fiddle outputs `/Users/miburda/Library/Application Support/Electron`

### Testcase Gist URL

_No response_

### Additional Information

Seems to be regressed by #29649. Happens both before and after `app.whenReady()`.
shell/browser/electron_browser_context.cc
auto prefs_path = GetPath().Append(FILE_PATH_LITERAL("Preferences"));
  base::ThreadRestrictions::ScopedAllowIO allow_io;
  PrefServiceFactory prefs_factory;
  scoped_refptr<JsonPrefStore> pref_store =
      base::MakeRefCounted<JsonPrefStore>(prefs_path);
  pref_store->ReadPrefs();  
  prefs_factory.set_user_prefs(pref_store);
#if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
  if (!in_memory_) {
    auto* ext_pref_store = new ExtensionPrefStore(
        ExtensionPrefValueMapFactory::GetForBrowserContext(this),
        IsOffTheRecord());
    prefs_factory.set_extension_prefs(ext_pref_store);
  }
#endif
#if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS) || \
    BUILDFLAG(ENABLE_BUILTIN_SPELLCHECKER)
  auto registry = base::MakeRefCounted<user_prefs::PrefRegistrySyncable>();
#else
  auto registry = base::MakeRefCounted<PrefRegistrySimple>();
#endif
  registry->RegisterFilePathPref(prefs::kSelectFileLastDirectory,
                                 base::FilePath());
  base::FilePath download_dir;
  base::PathService::Get(chrome::DIR_DEFAULT_DOWNLOADS, &download_dir);