Add policy domain for signin screen apps

chrome/browser/chromeos/policy/device_local_account_extension_tracker.cc

 // Copyright 2014 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.
 
 #include "chrome/browser/chromeos/policy/device_local_account_extension_tracker.h"
 
 #include "base/logging.h"
 #include "base/values.h"
 #include "chrome/browser/chromeos/policy/device_local_account.h"
 #include "chrome/browser/extensions/policy_handlers.h"
@@ skipping 18 matching lines @@
     PolicyNamespace ns(POLICY_DOMAIN_EXTENSIONS, account.kiosk_app_id);
     schema_registry_->RegisterComponent(ns, Schema());
   } else if (account.type == DeviceLocalAccount::TYPE_PUBLIC_SESSION) {
     // For public sessions, track the value of the ExtensionInstallForcelist
     // policy.
     store_->AddObserver(this);
     UpdateFromStore();
   } else {
     NOTREACHED();
   }
-
-  schema_registry_->SetReady(POLICY_DOMAIN_EXTENSIONS);

[emaxx, 2016/10/21 03:37:53]

It seems that these two lines may be actually safely removed: the same operation
is also performed in the DeviceLocalAccountPolicyBroker class (in its
constructor), which is the only owner of instances of this class.

 }
 
 DeviceLocalAccountExtensionTracker::~DeviceLocalAccountExtensionTracker() {
   store_->RemoveObserver(this);
 }
 
 void DeviceLocalAccountExtensionTracker::OnStoreLoaded(
     CloudPolicyStore* store) {
   UpdateFromStore();
 }
@@ skipping 37 matching lines @@
     }
     schema_registry_->RegisterComponent(ns, Schema());
   }
 
   // Removing an extension from a public session at runtime can happen but is
   // a rare event. In that case we leave the extension ID in the SchemaRegistry,
   // and it will be purged on the next restart.
 }
 
 }  // namespace policy