Put Kiosk App parameters into device settings.

chrome/browser/chromeos/policy/proto/chrome_device_policy.proto

 // Copyright (c) 2012 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.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 
 package enterprise_management;
 
@@ skipping 211 matching lines @@
   // the timezone and the change is persistent. Thus a change by one user
   // affects the login-screen and all other users.
   optional string timezone = 1;
 }
 
 // Describes a single device-local account.
 message DeviceLocalAccountInfoProto {
   // Identifier for the device-local account. Account identifiers loosely follow
   // the conventions for email addresses as specified by RFC 5322, e.g. local
   // (user name) and domain parts, separated by the '@' character.
-  // Policy-configured device-local accounts are on the same domain that the
-  // device is enrolled to. In contrast to RFC 5322 (which is more restrictive),
-  // the local part may contain any characters other than '@'.
+  //
+  // Device-local accounts are within subdomains of localhost:
+  //  * The public-accounts.localhost domain indicates a Public Account. This is
+  //    a special account type providing login-less, ephemeral,
+  //    policy-preconfigured browsing sessions.
+  //  * Legacy policy-configured Public Accounts are on the same domain that the
+  //    device is enrolled to. In contrast to RFC 5322 (which is more
+  //    restrictive), the local part may contain any characters other than '@'.
+  //    Legacy account identifiers of the form user@domain are treated as if
+  //    they were specified as user@domain.public-accounts.localhost.
+  //  * <appid>@kiosk-apps.localhost is used for configuring Kiosk Apps, which
+  //    may be started from the login screen and run the specified application
+  //    in full-screen mode. <appid> is the standard 32-character Chrome App
+  //    identifier.
   optional string id = 1;
 }
 
 message DeviceLocalAccountsProto {
   // The list of device-local accounts (i.e. accounts without an associated
   // cloud-backed profile) that are available on the device.
   repeated DeviceLocalAccountInfoProto account = 1;
 
   // The identifier of the device-local account to which the device
   // should be logged in automatically.  Should be equal to one of the
   // ids in DeviceLocalAccountInfoProto.
   optional string auto_login_id = 2;
 
   // The amount of time, in milliseconds, that should elapse at the signin
   // screen without user interaction before automatically logging in.
   optional int64 auto_login_delay = 3;
+
+  // Whether the keyboard shortcut to prevent zero-delay auto-login should be
+  // enabled or not. If this keyboard shortcut is engaged, the auto-login will
+  // be delayed by 3 minutes so administrators can log in or make configuration
+  // changes.
+  optional bool enable_auto_login_bailout = 4 [default = true];
 }
 
 message AllowRedeemChromeOsRegistrationOffersProto {
   // Chrome OS Registration service provides way for chromeos device users
   // to redeem electronic offers provided by service provider.
   // This value determines if users are allowed to redeem offers through
   // Chrome OS Registration service.
   optional bool allow_redeem_offers = 1 [default = false];
 }
 
@@ skipping 50 matching lines @@
   optional StartUpUrlsProto start_up_urls = 18;
   optional PinnedAppsProto pinned_apps = 19;
   optional SystemTimezoneProto system_timezone = 20;
   optional DeviceLocalAccountsProto device_local_accounts = 21;
   optional AllowRedeemChromeOsRegistrationOffersProto allow_redeem_offers = 22;
   optional StartUpFlagsProto start_up_flags = 23;
   optional UptimeLimitProto uptime_limit = 24;
   optional VariationsParameterProto variations_parameter = 25;
   optional AttestationSettingsProto attestation_settings = 26;
 }