Google OAuth Device Flow support for FNL

services/authentication/credentials_impl_db.mojom

+// 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.
+
+module authentication;
+
+// Specifies if the type of stored credential is a plain text password,
+// password in encrypted form, fully scoped master OAuth token or
+// downscoped OAuth token.
+enum CredentialType {
+  DOWNSCOPED_OAUTH_REFRESH_TOKEN = 1
+};
+
+// Specifies the type of identity provider for authenticating user.
+enum AuthProvider {
+  GOOGLE = 1
+};
+
+// This struct is used to persist long lived credentials for each user and is
+// not passed between services.
+struct Credentials {
+  // The type of authentication service provider such as Google, Facebook,
+  // Twitter, or Amazon.
+  AuthProvider auth_provider;
+  // Password or equivalent token grant that acts as the key to user data such
+  // as encrypted password or fully scoped master OAuth token.
+  string token;
+  // Type of stored credential.
+  CredentialType credential_type;
+  // List of permissible scopes for this saved grant.
+  string scopes;
+};
+
+// Database for the credentials database implementation.
+struct CredentialStore {
+  // Version of the database.
+  uint32 version;
+  // Map from user account to credentials. User account is identified by a
+  // user's unique account name such as email id.
+  map<string, Credentials> credentials;
+};