Sync: Avoid 3 passes over SyncDarta DB when loading the directory from the disk

sync/syncable/invalid_directory_backing_store.cc

Index: sync/syncable/invalid_directory_backing_store.cc
diff --git a/sync/syncable/invalid_directory_backing_store.cc b/sync/syncable/invalid_directory_backing_store.cc
index 63455217978fc77f2b5669e9a1cc3d46e840e9a1..1844d846d2975fcaf2acbf93469e398aefb5cbbf 100644
--- a/sync/syncable/invalid_directory_backing_store.cc
+++ b/sync/syncable/invalid_directory_backing_store.cc
@@ -17,6 +17,7 @@ InvalidDirectoryBackingStore::~InvalidDirectoryBackingStore() {
 DirOpenResult InvalidDirectoryBackingStore::Load(
     Directory::MetahandlesMap* handles_map,
     JournalIndex* delete_journals,
+    MetahandleSet* metahandles_to_purge,
     Directory::KernelLoadInfo* kernel_load_info) {
   return FAILED_OPEN_DATABASE;
 }