[Sync] Allow sync start without sign-in if the local sync backend is on.

components/sync/engine/engine_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 "components/sync/engine/engine_components_factory_impl.h"
 
 #include "base/memory/ptr_util.h"
 #include "components/sync/engine_impl/backoff_delay_provider.h"
 #include "components/sync/engine_impl/cycle/sync_cycle_context.h"
 #include "components/sync/engine_impl/sync_scheduler_impl.h"
@@ skipping 10 matching lines @@
 
 EngineComponentsFactoryImpl::EngineComponentsFactoryImpl(
     const Switches& switches)
     : switches_(switches) {}
 
 EngineComponentsFactoryImpl::~EngineComponentsFactoryImpl() {}
 
 std::unique_ptr<SyncScheduler> EngineComponentsFactoryImpl::BuildScheduler(
     const std::string& name,
     SyncCycleContext* context,
-    CancelationSignal* cancelation_signal) {
+    CancelationSignal* cancelation_signal,
+    bool ignore_auth_credentials) {
   std::unique_ptr<BackoffDelayProvider> delay(
       BackoffDelayProvider::FromDefaults());
 
   if (switches_.backoff_override == BACKOFF_SHORT_INITIAL_RETRY_OVERRIDE) {
     delay.reset(BackoffDelayProvider::WithShortInitialRetryOverride());
   }
 
   std::unique_ptr<SyncSchedulerImpl> scheduler =
       base::MakeUnique<SyncSchedulerImpl>(name, delay.release(), context,
-                                          new Syncer(cancelation_signal));
+                                          new Syncer(cancelation_signal),
+                                          ignore_auth_credentials);
   if (switches_.nudge_delay == NudgeDelay::SHORT_NUDGE_DELAY) {
     // Set the default nudge delay to 0 because the default is used as a floor
     // for override values, and we don't want the below override to be ignored.
     scheduler->SetDefaultNudgeDelay(TimeDelta::FromMilliseconds(0));
     // Only protocol types can have their delay customized.
     ModelTypeSet protocol_types = syncer::ProtocolTypes();
     std::map<ModelType, base::TimeDelta> nudge_delays;
     for (ModelTypeSet::Iterator it = protocol_types.First(); it.Good();
          it.Inc()) {
       nudge_delays[it.Get()] =
@@ skipping 34 matching lines @@
     return std::unique_ptr<syncable::DirectoryBackingStore>();
   }
 }
 
 EngineComponentsFactory::Switches EngineComponentsFactoryImpl::GetSwitches()
     const {
   return switches_;
 }
 
 }  // namespace syncer