sync: Gracefully handle very early shutdown

sync/internal_api/internal_components_factory_impl.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 "sync/internal_api/public/internal_components_factory_impl.h"
 
 #include "sync/engine/backoff_delay_provider.h"
 #include "sync/engine/syncer.h"
 #include "sync/engine/sync_scheduler_impl.h"
 #include "sync/sessions/sync_session_context.h"
 #include "sync/syncable/on_disk_directory_backing_store.h"
 
 using base::TimeDelta;
 
 namespace syncer {
 
 InternalComponentsFactoryImpl::InternalComponentsFactoryImpl(
     const Switches& switches) : switches_(switches) {
 }
 
 InternalComponentsFactoryImpl::~InternalComponentsFactoryImpl() { }
 
 scoped_ptr<SyncScheduler> InternalComponentsFactoryImpl::BuildScheduler(
-    const std::string& name, sessions::SyncSessionContext* context) {
+    const std::string& name,
+    sessions::SyncSessionContext* context,
+    CancelationSignal* cancelation_signal) {
 
   scoped_ptr<BackoffDelayProvider> delay(BackoffDelayProvider::FromDefaults());
 
   if (switches_.backoff_override == BACKOFF_SHORT_INITIAL_RETRY_OVERRIDE)
     delay.reset(BackoffDelayProvider::WithShortInitialRetryOverride());
 
-  return scoped_ptr<SyncScheduler>(
-      new SyncSchedulerImpl(name, delay.release(), context, new Syncer()));
+  return scoped_ptr<SyncScheduler>(new SyncSchedulerImpl(
+          name,
+          delay.release(),
+          context,
+          new Syncer(cancelation_signal)));
 }
 
 scoped_ptr<sessions::SyncSessionContext>
 InternalComponentsFactoryImpl::BuildContext(
     ServerConnectionManager* connection_manager,
     syncable::Directory* directory,
     const std::vector<ModelSafeWorker*>& workers,
     ExtensionsActivity* extensions_activity,
     const std::vector<SyncEngineEventListener*>& listeners,
     sessions::DebugInfoGetter* debug_info_getter,
@@ skipping 16 matching lines @@
   return scoped_ptr<syncable::DirectoryBackingStore>(
       new syncable::OnDiskDirectoryBackingStore(dir_name, backing_filepath));
 }
 
 InternalComponentsFactory::Switches
 InternalComponentsFactoryImpl::GetSwitches() const {
   return switches_;
 }
 
 }  // namespace syncer