refactor: move safe_storage functions into anonymous namespace (#43032)

shell/browser/api/electron_api_safe_storage.h

@@ -1,21 +0,0 @@
-// Copyright (c) 2021 Slack Technologies, Inc.
-// Use of this source code is governed by the MIT license that can be
-// found in the LICENSE file.
-
-#ifndef ELECTRON_SHELL_BROWSER_API_ELECTRON_API_SAFE_STORAGE_H_
-#define ELECTRON_SHELL_BROWSER_API_ELECTRON_API_SAFE_STORAGE_H_
-
-#include "base/dcheck_is_on.h"
-
-namespace electron::safestorage {
-
-// Used in a DCHECK to validate that our assumption that the network context
-// manager has initialized before app ready holds true. Only used in the
-// testing build
-#if DCHECK_IS_ON()
-void SetElectronCryptoReady(bool ready);
-#endif
-
-}  // namespace electron::safestorage
-
-#endif  // ELECTRON_SHELL_BROWSER_API_ELECTRON_API_SAFE_STORAGE_H_