Wire sync shutdown reason from PSS all the way down to sync manager.

sync/internal_api/sync_manager_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/sync_manager_impl.h"
 
 #include <string>
 
 #include "base/base64.h"
 #include "base/bind.h"
@@ skipping 587 matching lines @@
 void SyncManagerImpl::AddObserver(SyncManager::Observer* observer) {
   DCHECK(thread_checker_.CalledOnValidThread());
   observers_.AddObserver(observer);
 }
 
 void SyncManagerImpl::RemoveObserver(SyncManager::Observer* observer) {
   DCHECK(thread_checker_.CalledOnValidThread());
   observers_.RemoveObserver(observer);
 }
 
-void SyncManagerImpl::ShutdownOnSyncThread() {
+void SyncManagerImpl::ShutdownOnSyncThread(ShutdownReason reason) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   // Prevent any in-flight method calls from running.  Also
   // invalidates |weak_handle_this_| and |change_observer_|.
   weak_ptr_factory_.InvalidateWeakPtrs();
   js_mutation_event_observer_.InvalidateWeakPtrs();
 
   scheduler_.reset();
   session_context_.reset();
   model_type_registry_.reset();
@@ skipping 528 matching lines @@
 int SyncManagerImpl::GetDefaultNudgeDelay() {
   return kDefaultNudgeDelayMilliseconds;
 }
 
 // static.
 int SyncManagerImpl::GetPreferencesNudgeDelay() {
   return kPreferencesNudgeDelayMilliseconds;
 }
 
 }  // namespace syncer