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

sync/syncable/scoped_index_updater.h

 // 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.
 
 #ifndef SYNC_SYNCABLE_SCOPED_INDEX_UPDATER_H_
 #define SYNC_SYNCABLE_SCOPED_INDEX_UPDATER_H_
 
 #include "sync/syncable/directory.h"
 
+namespace syncer {
 namespace syncable {
 class ScopedKernelLock;
 
 // A ScopedIndexUpdater temporarily removes an entry from an index,
 // and restores it to the index when the scope exits.  This simplifies
 // the common pattern where items need to be removed from an index
 // before updating the field.
 //
 // This class is parameterized on the Indexer traits type, which
 // must define a Comparator and a static bool ShouldInclude
@@ skipping 24 matching lines @@
     }
   }
  private:
   // The entry that was temporarily removed from the index.
   EntryKernel* entry_;
   // The index which we are updating.
   typename Index<Indexer>::Set* const index_;
 };
 
 }  // namespace syncable
+}  // namespace syncer
 
 #endif // SYNC_SYNCABLE_SCOPED_INDEX_UPDATER_H_