[Sync] Refactor GetEncryptedTypes usage.

sync/internal_api/public/base_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_INTERNAL_API_PUBLIC_BASE_TRANSACTION_H_
 #define SYNC_INTERNAL_API_PUBLIC_BASE_TRANSACTION_H_
 
 #include "sync/internal_api/public/user_share.h"
 
+#include "sync/internal_api/public/base/model_type.h"
 #include "sync/util/cryptographer.h"
 
 namespace syncer {
 
 namespace syncable {
 class BaseTransaction;
 class Directory;
 }
 
 // Sync API's BaseTransaction, ReadTransaction, and WriteTransaction allow for
 // batching of several read and/or write operations.  The read and write
 // operations are performed by creating ReadNode and WriteNode instances using
 // the transaction. These transaction classes wrap identically named classes in
 // syncable, and are used in a similar way. Unlike syncable::BaseTransaction,
 // whose construction requires an explicit syncable::Directory, a sync
 // API BaseTransaction is created from a UserShare object.
 class BaseTransaction {
  public:
   // Provide access to the underlying syncable objects from BaseNode.
   virtual syncable::BaseTransaction* GetWrappedTrans() const = 0;
   Cryptographer* GetCryptographer() const;
+  ModelTypeSet GetEncryptedTypes() const;
 
   syncable::Directory* GetDirectory() const {
     return directory_;
   }
 
  protected:
   explicit BaseTransaction(UserShare* share);
   virtual ~BaseTransaction();
 
   BaseTransaction() : directory_(NULL) { }
 
  private:
   syncable::Directory* directory_;
 
   DISALLOW_COPY_AND_ASSIGN(BaseTransaction);
 };
 
-ModelTypeSet GetEncryptedTypes(const BaseTransaction* trans);
-
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_BASE_TRANSACTION_H_