Create setting that disables password stores

components/os_crypt/key_storage_util_linux.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_OS_CRYPT_KEY_STORAGE_UTIL_LINUX_H_
 #define COMPONENTS_OS_CRYPT_KEY_STORAGE_UTIL_LINUX_H_
 
 #include <string>
 
 #include "base/nix/xdg_util.h"
 
+namespace base {
+class FilePath;
+}
+
 namespace os_crypt {
 
 // The supported Linux backends for storing passwords.
 enum class SelectedLinuxBackend {
   DEFER,  // No selection
   BASIC_TEXT,
   GNOME_ANY,  // GNOME_KEYRING or GNOME_LIBSECRET, whichever is available.
   GNOME_KEYRING,
   GNOME_LIBSECRET,
   KWALLET,
   KWALLET5,
 };
 
 // Decide which backend to target. |type| is checked first. If it does not
-// match a supported backend, |desktop_env| will be used to decide.
+// match a supported backend and |use_backend| is true, |desktop_env| will be
+// used to decide.
 // TODO(crbug/571003): This is exposed as a utility only for password manager to
 // use. It should be merged into key_storage_linux, once no longer needed in
 // password manager.
 SelectedLinuxBackend SelectBackend(const std::string& type,
+                                   bool use_backend,
                                    base::nix::DesktopEnvironment desktop_env);
 
+// Set the setting that disables using OS-level encryption. If |use| is true,
+// a backend will be used.
+bool WriteBackendUse(const base::FilePath& user_data_dir, bool use);
+
+// Decide whether the backend should be used based on the setting.
+bool GetBackendUse(const base::FilePath& user_data_dir);
+
 }  // namespace os_crypt
 
 #endif  // COMPONENTS_OS_CRYPT_KEY_STORAGE_UTIL_LINUX_H_