Persist Directory to disk when the app is backgrounded.

chrome/browser/sync/glue/sync_backend_host_core.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_core.h"
 
 #include "base/files/file_util.h"
 #include "base/metrics/histogram.h"
 #include "chrome/browser/sync/glue/device_info.h"
 #include "chrome/browser/sync/glue/invalidation_adapter.h"
 #include "chrome/browser/sync/glue/sync_backend_registrar.h"
 #include "chrome/browser/sync/glue/synced_device_tracker.h"
 #include "chrome/common/chrome_version_info.h"
 #include "components/invalidation/invalidation_util.h"
 #include "components/invalidation/object_id_invalidation_map.h"
 #include "sync/internal_api/public/events/protocol_event.h"
 #include "sync/internal_api/public/http_post_provider_factory.h"
 #include "sync/internal_api/public/internal_components_factory.h"
 #include "sync/internal_api/public/sessions/commit_counters.h"
 #include "sync/internal_api/public/sessions/status_counters.h"
 #include "sync/internal_api/public/sessions/sync_session_snapshot.h"
 #include "sync/internal_api/public/sessions/update_counters.h"
 #include "sync/internal_api/public/sync_context_proxy.h"
 #include "sync/internal_api/public/sync_manager.h"
 #include "sync/internal_api/public/sync_manager_factory.h"
+#include "sync/syncable/directory.h"
 #include "url/gurl.h"
 
 // Helper macros to log with the syncer thread name; useful when there
 // are multiple syncers involved.
 
 #define SLOG(severity) LOG(severity) << name_ << ": "
 
 #define SDVLOG(verbose_level) DVLOG(verbose_level) << name_ << ": "
 
 static const int kSaveChangesIntervalSeconds = 10;
@@ skipping 619 matching lines @@
 }
 
 void SyncBackendHostCore::DoRetryConfiguration(
     const base::Closure& retry_callback) {
   DCHECK_EQ(base::MessageLoop::current(), sync_loop_);
   host_.Call(FROM_HERE,
              &SyncBackendHostImpl::RetryConfigurationOnFrontendLoop,
              retry_callback);
 }
 
+void SyncBackendHostCore::DoFlushDirectory() {
+  syncer::syncable::Directory* directory =

[maniscalco, 2014/09/12 17:42:19]

It would be a good idea to add a DCHECK to ensure this is called on the correct
thread (similar to what's done in other methods like DoRetryConfiguraiton):

DCHECK_EQ(base::MessageLoop::current(), sync_loop_);

[maxbogue, 2014/09/12 18:48:14]

Done.

+      sync_manager()->GetUserShare()->directory.get();
+  if (directory != NULL) {
+    directory->SaveChanges();
+  }
+}
+
 void SyncBackendHostCore::SendBufferedProtocolEventsAndEnableForwarding() {
   DCHECK_EQ(base::MessageLoop::current(), sync_loop_);
   forward_protocol_events_ = true;
 
   if (sync_manager_) {
     // Grab our own copy of the buffered events.
     // The buffer is not modified by this operation.
     std::vector<syncer::ProtocolEvent*> buffered_events;
     sync_manager_->GetBufferedProtocolEvents().release(&buffered_events);
 
@@ skipping 81 matching lines @@
       base::TimeDelta::FromSeconds(kSaveChangesIntervalSeconds),
       this, &SyncBackendHostCore::SaveChanges);
 }
 
 void SyncBackendHostCore::SaveChanges() {
   DCHECK_EQ(base::MessageLoop::current(), sync_loop_);
   sync_manager_->SaveChanges();
 }
 
 }  // namespace browser_sync