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

sync/syncable/write_transaction.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_WRITE_TRANSACTION_H_
 #define SYNC_SYNCABLE_WRITE_TRANSACTION_H_
 #pragma once
 
 #include "sync/syncable/base_transaction.h"
 #include "sync/syncable/entry_kernel.h"
 
+namespace syncer {
 namespace syncable {
 
 // Locks db in constructor, unlocks in destructor.
 class WriteTransaction : public BaseTransaction {
  public:
   WriteTransaction(const tracked_objects::Location& from_here,
                    WriterTag writer, Directory* directory);
 
   virtual ~WriteTransaction();
 
@@ skipping 15 matching lines @@
       const ImmutableEntryKernelMutationMap& mutations);
 
   // Only the original fields are filled in until |RecordMutations()|.
   // We use a mutation map instead of a kernel set to avoid copying.
   EntryKernelMutationMap mutations_;
 
   DISALLOW_COPY_AND_ASSIGN(WriteTransaction);
 };
 
 }  // namespace syncable
+}  // namespace syncer
 
 #endif //  SYNC_SYNCABLE_WRITE_TRANSACTION_H_