Add a callback to RemoteFileSyncService for reporting errors.

chrome/browser/sync_file_system/sync_file_system_service.cc

Index: chrome/browser/sync_file_system/sync_file_system_service.cc
diff --git a/chrome/browser/sync_file_system/sync_file_system_service.cc b/chrome/browser/sync_file_system/sync_file_system_service.cc
index c4219ece95cdbc2a0aa5c27941d5012840528792..7da2bdaaa77ba29423036408fb02231e310508cb 100644
--- a/chrome/browser/sync_file_system/sync_file_system_service.cc
+++ b/chrome/browser/sync_file_system/sync_file_system_service.cc
@@ -56,8 +56,11 @@ void SyncFileSystemService::InitializeForApp(
   local_file_service_->MaybeInitializeFileSystemContext(
       app_origin, service_name, file_system_context, callback);
 
-  if (remote_file_service_)
-    remote_file_service_->RegisterOriginForTrackingChanges(app_origin);
+  if (remote_file_service_) {
+    // TODO(tzik): Handle errors in the completion callback.
+    remote_file_service_->RegisterOriginForTrackingChanges(
+        app_origin, fileapi::SyncStatusCallback());
+  }
 }
 
 void SyncFileSystemService::GetConflictFiles(