[Sync] Stop deleting LevelDB files when deleting Directory

components/sync/syncable/directory.h

 // 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.
 
 #ifndef COMPONENTS_SYNC_SYNCABLE_DIRECTORY_H_
 #define COMPONENTS_SYNC_SYNCABLE_DIRECTORY_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 509 matching lines @@
 
   bool ReindexParentId(BaseWriteTransaction* trans,
                        EntryKernel* const entry,
                        const Id& new_parent_id);
 
   // Accessors for the underlying Kernel. Although these are public methods, the
   // number of classes that call these should be limited.
   Kernel* kernel();
   const Kernel* kernel() const;
 
+  // Delete the directory database files from the sync data folder to cleanup
+  // backend data. This should happen the first time sync is enabled for a user,
+  // to prevent accidentally reusing old sync data, as well as shutdown when the
+  // user is no longer syncing.
+  static void DeleteDirectoryFiles(const base::FilePath& directory_path);
+
  private:
   friend class SyncableDirectoryTest;
   friend class syncer::TestUserShare;
   FRIEND_TEST_ALL_PREFIXES(SyncableDirectoryTest, ManageDeleteJournals);
   FRIEND_TEST_ALL_PREFIXES(SyncableDirectoryTest,
                            TakeSnapshotGetsAllDirtyHandlesTest);
   FRIEND_TEST_ALL_PREFIXES(SyncableDirectoryTest,
                            TakeSnapshotGetsOnlyDirtyHandlesTest);
   FRIEND_TEST_ALL_PREFIXES(SyncableDirectoryTest,
                            TakeSnapshotGetsMetahandlesToPurge);
@@ skipping 121 matching lines @@
 
   base::WeakPtrFactory<Directory> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Directory);
 };
 
 }  // namespace syncable
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_SYNCABLE_DIRECTORY_H_