[Sync] Move sync/{internal_api,syncable} into syncer namespace

sync/syncable/on_disk_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/syncable/on_disk_directory_backing_store.h"
 
 #include "base/logging.h"
 
+namespace syncer {
 namespace syncable {
 
 OnDiskDirectoryBackingStore::OnDiskDirectoryBackingStore(
     const std::string& dir_name, const FilePath& backing_filepath)
     : DirectoryBackingStore(dir_name),
       backing_filepath_(backing_filepath) {
   db_->set_exclusive_locking();
   db_->set_page_size(4096);
 }
 
@@ skipping 13 matching lines @@
     return FAILED_DATABASE_CORRUPT;
   if (!LoadEntries(entry_bucket))
     return FAILED_DATABASE_CORRUPT;
   if (!LoadInfo(kernel_load_info))
     return FAILED_DATABASE_CORRUPT;
 
   return OPENED;
 }
 
 }  // namespace syncable
+}  // namespace syncer