[sync] Set up notification-free infra for triggering local sync refresh

chrome/browser/sync/glue/sync_backend_host_impl.cc

 // Copyright 2013 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/sync/glue/sync_backend_host_impl.h"
 
 #include "base/command_line.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 156 matching lines @@
       sync_prefs_->GetEncryptionBootstrapToken(),
       sync_prefs_->GetKeystoreEncryptionBootstrapToken(),
       scoped_ptr<InternalComponentsFactory>(
           new syncer::InternalComponentsFactoryImpl(factory_switches))
           .Pass(),
       unrecoverable_error_handler, report_unrecoverable_error_function,
       saved_nigori_state.Pass(), clear_data_option, invalidation_versions));
   InitCore(init_opts.Pass());
 }
 
+void SyncBackendHostImpl::TriggerRefresh(const syncer::ModelTypeSet& types) {
+  DCHECK(ui_thread_->BelongsToCurrentThread());
+  registrar_->sync_thread()->task_runner()->PostTask(
+      FROM_HERE,
+      base::Bind(&SyncBackendHostCore::DoRefreshTypes, core_.get(), types));
+}
+
 void SyncBackendHostImpl::UpdateCredentials(
     const syncer::SyncCredentials& credentials) {
   DCHECK(registrar_->sync_thread()->IsRunning());
   registrar_->sync_thread()->task_runner()->PostTask(
       FROM_HERE, base::Bind(&SyncBackendHostCore::DoUpdateCredentials,
                             core_.get(), credentials));
 }
 
 void SyncBackendHostImpl::StartSyncingWithServer() {
   SDVLOG(1) << "SyncBackendHostImpl::StartSyncingWithServer called.";
@@ skipping 435 matching lines @@
   }
 
   if (!ready_task.is_null())
     ready_task.Run(succeeded_configuration_types, failed_configuration_types);
 }
 
 void SyncBackendHostImpl::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
-  DCHECK(ui_thread_->BelongsToCurrentThread());
   DCHECK_EQ(type, chrome::NOTIFICATION_SYNC_REFRESH_LOCAL);
 
   content::Details<const syncer::ModelTypeSet> state_details(details);
   const syncer::ModelTypeSet& types = *(state_details.ptr());
-  registrar_->sync_thread()->task_runner()->PostTask(
-      FROM_HERE,
-      base::Bind(&SyncBackendHostCore::DoRefreshTypes, core_.get(), types));
+  TriggerRefresh(types);
 }
 
 void SyncBackendHostImpl::AddExperimentalTypes() {
   CHECK(initialized());
   syncer::Experiments experiments;
   if (core_->sync_manager()->ReceivedExperiment(&experiments))
     frontend_->OnExperimentsChanged(experiments);
 }
 
 void SyncBackendHostImpl::HandleInitializationSuccessOnFrontendLoop(
@@ skipping 264 matching lines @@
     const syncer::SyncManager::ClearServerDataCallback& frontend_callback) {
   DCHECK(ui_thread_->BelongsToCurrentThread());
   frontend_callback.Run();
 }
 
 }  // namespace browser_sync
 
 #undef SDVLOG
 
 #undef SLOG