Add device policy: Kiosk Virtual Keyboard Layout.

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

 // Copyright 2013 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 103 matching lines @@
   // This field was added but never used and there are no plans to support it
   // eventually either.
   optional bool OBSOLETE_online_only = 3 [deprecated = true];
 }
 
 message AppPackProto {
   // List of extensions to install as part of the AppPack.
   repeated AppPackEntryProto app_pack = 1;
 }
 
+message KioskVirtualKeyboardProto {
+  // This is a special policy for kiosk mode that specifies whether the virtual
+  // keyboard should always be enabled. If non-null this should be a valid
+  // keyboard layout.
+  optional string layout = 1;
+}
+
 // This is a special policy for kiosk/retail mode that specifies what apps
 // should be pinned to the launcher. For regular accounts, pinned apps are
 // controlled through user policy.
 message PinnedAppsProto {
   // App IDs for the apps to pin.
   repeated string app_id = 1;
 }
 
 message ForcedLogoutTimeoutsProto {
   // All timeouts are specified in milliseconds.
@@ skipping 465 matching lines @@
   optional StartUpFlagsProto start_up_flags = 23;
   optional UptimeLimitProto uptime_limit = 24;
   optional VariationsParameterProto variations_parameter = 25;
   optional AttestationSettingsProto attestation_settings = 26;
   optional AccessibilitySettingsProto accessibility_settings = 27;
   optional SupervisedUsersSettingsProto supervised_users_settings = 28;
   optional LoginScreenPowerManagementProto login_screen_power_management = 29;
   optional SystemUse24HourClockProto use_24hour_clock = 30;
   optional AutoCleanupSettigsProto auto_clean_up_settings = 31;
   optional SystemSettingsProto system_settings = 32;
+  optional KioskVirtualKeyboardProto kiosk_virtual_keyboard = 33;
 }