[Sync] Adjust types to configure during shutdown

components/sync/engine_impl/syncer.cc

 // 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.
 
 #include "components/sync/engine_impl/syncer.h"
 
 #include <memory>
 
 #include "base/auto_reset.h"
 #include "base/logging.h"
@@ skipping 64 matching lines @@
 }
 
 bool Syncer::ConfigureSyncShare(
     ModelTypeSet request_types,
     sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source,
     SyncCycle* cycle) {
   base::AutoReset<bool> is_syncing(&is_syncing_, true);
   VLOG(1) << "Configuring types " << ModelTypeSetToString(request_types);
   HandleCycleBegin(cycle);
   ConfigureGetUpdatesDelegate configure_delegate(source);
+
+  // It is possible during shutdown that datatypes get unregistered from
+  // ModelTypeRegistry before scheduled configure sync cycle gets executed.
+  // When it happens we should adjust set of types to download to only include
+  // registered types.
+  if (cancelation_signal_->IsSignalled())
+    request_types.RetainAll(cycle->context()->GetEnabledTypes());
+
   GetUpdatesProcessor get_updates_processor(
       cycle->context()->model_type_registry()->update_handler_map(),
       configure_delegate);
   DownloadAndApplyUpdates(&request_types, cycle, &get_updates_processor,
                           kCreateMobileBookmarksFolder);
   return HandleCycleEnd(cycle, source);
 }
 
 bool Syncer::PollSyncShare(ModelTypeSet request_types, SyncCycle* cycle) {
   base::AutoReset<bool> is_syncing(&is_syncing_, true);
@@ skipping 96 matching lines @@
 }
 
 bool Syncer::PostClearServerData(SyncCycle* cycle) {
   DCHECK(cycle);
   ClearServerData clear_server_data(cycle->context()->account_name());
   const SyncerError post_result = clear_server_data.SendRequest(cycle);
   return post_result == SYNCER_OK;
 }
 
 }  // namespace syncer