Add device policy to disallow shutdown

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 565 matching lines @@
 }
 
 // Settings that control login for SAML users.
 message SAMLSettingsProto {
   // Whether cookies set by a SAML IdP should be transferred to users' profiles
   // every time a user authenticates via SAML during login. If false, cookies
   // are transferred during each user's first login only.
   optional bool transfer_saml_cookies = 1;
 }
 
+message ShutdownIsRebootProto {
+  // Determines whether the device may be shut down. If this flag is set to true

[bartfab (slow), 2014/12/08 16:49:44]

Nit: s/true/true,/

[cschuet (SLOW), 2014/12/08 18:57:04]

Done.

+  // shutdown is forbidden and UI elements trigger a device reboot instead of a
+  // power off. This policy controls shut down via the UI only.

[bartfab (slow), 2014/12/08 16:49:44]

Nit: s/shut down/shutdown/

[cschuet (SLOW), 2014/12/08 18:57:04]

Done.

+  optional bool shutdown_is_reboot = 1 [default = false];
+}
+
 message ChromeDeviceSettingsProto {
   optional DevicePolicyRefreshRateProto device_policy_refresh_rate = 1;
   optional UserWhitelistProto user_whitelist = 2;
   optional GuestModeEnabledProto guest_mode_enabled = 3;
   optional DeviceProxySettingsProto device_proxy_settings = 4;
   optional CameraEnabledProto camera_enabled = 5;
   optional ShowUserNamesOnSigninProto show_user_names = 6;
   optional DataRoamingEnabledProto data_roaming_enabled = 7;
   optional AllowNewUsersProto allow_new_users = 8;
   optional MetricsEnabledProto metrics_enabled = 9;
@@ skipping 14 matching lines @@
   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 SAMLSettingsProto saml_settings = 33;
+  optional ShutdownIsRebootProto shutdown_is_reboot = 34;
 }