Persist Directory to disk when the app is backgrounded.

chrome/browser/sync/glue/sync_backend_host_core.cc

Index: chrome/browser/sync/glue/sync_backend_host_core.cc
diff --git a/chrome/browser/sync/glue/sync_backend_host_core.cc b/chrome/browser/sync/glue/sync_backend_host_core.cc
index 2a78040131e0e7894375a1f11fa40c2e0285eb66..7acdbd2c0679f5d4236cdaae06602a607d24b54f 100644
--- a/chrome/browser/sync/glue/sync_backend_host_core.cc
+++ b/chrome/browser/sync/glue/sync_backend_host_core.cc
@@ -23,6 +23,7 @@
 #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
@@ -662,6 +663,14 @@ void SyncBackendHostCore::DoRetryConfiguration(
              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;