Persist Directory to disk when the app is backgrounded.

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/logging.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
@@ skipping 502 matching lines @@
     NOTREACHED();
   }
 }
 
 SyncedDeviceTracker* SyncBackendHostImpl::GetSyncedDeviceTracker() const {
   if (!initialized())
     return NULL;
   return core_->synced_device_tracker();
 }
 
+void SyncBackendHostImpl::FlushDirectory() const {

[Nicolas Zea, 2014/09/22 17:27:46]

DCHECK initialized()?

[maxbogue, 2014/09/30 00:26:32]

Done.

+  registrar_->sync_thread()->message_loop()->PostTask(FROM_HERE,
+      base::Bind(&SyncBackendHostCore::DoFlushDirectory, core_));
+}
+
 void SyncBackendHostImpl::RequestBufferedProtocolEventsAndEnableForwarding() {
   registrar_->sync_thread()->message_loop()->PostTask(
       FROM_HERE,
       base::Bind(
           &SyncBackendHostCore::SendBufferedProtocolEventsAndEnableForwarding,
           core_));
 }
 
 void SyncBackendHostImpl::DisableProtocolEventForwarding() {
   registrar_->sync_thread()->message_loop()->PostTask(
@@ skipping 351 matching lines @@
 
 base::MessageLoop* SyncBackendHostImpl::GetSyncLoopForTesting() {
   return registrar_->sync_thread()->message_loop();
 }
 
 }  // namespace browser_sync
 
 #undef SDVLOG
 
 #undef SLOG