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

sync/test/test_directory_backing_store.cc

 // Copyright (c) 2012 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 "sync/test/test_directory_backing_store.h"
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 
 namespace syncer {
 namespace syncable {
 
 TestDirectoryBackingStore::TestDirectoryBackingStore(
     const std::string& dir_name, sql::Connection* db)
   : DirectoryBackingStore(dir_name, db) {
 }
 
 TestDirectoryBackingStore::~TestDirectoryBackingStore() {
   // This variant of the DirectoryBackingStore does not own its connection, so
   // we take care to not delete it here.
   ignore_result(db_.release());
 }
 
 DirOpenResult TestDirectoryBackingStore::Load(
     Directory::MetahandlesMap* handles_map,
     JournalIndex* delete_journals,
+    MetahandleSet* metahandles_to_purge,
     Directory::KernelLoadInfo* kernel_load_info) {
   DCHECK(db_->is_open());
 
   if (!InitializeTables())
     return FAILED_OPEN_DATABASE;
 
-  if (!DropDeletedEntries())
-    return FAILED_DATABASE_CORRUPT;
-  if (!LoadEntries(handles_map))
+  if (!LoadEntries(handles_map, metahandles_to_purge))
     return FAILED_DATABASE_CORRUPT;
   if (!LoadDeleteJournals(delete_journals))
     return FAILED_DATABASE_CORRUPT;
   if (!LoadInfo(kernel_load_info))
     return FAILED_DATABASE_CORRUPT;
   if (!VerifyReferenceIntegrity(handles_map))
     return FAILED_DATABASE_CORRUPT;
 
   return OPENED;
 }
 
+bool TestDirectoryBackingStore::DeleteEntries(const MetahandleSet& handles) {
+  return DirectoryBackingStore::DeleteEntries(
+      DirectoryBackingStore::METAS_TABLE, handles);
+}
+
 }  // namespace syncable
 }  // namespace syncer