[Sync] Replace AttachmentIdSet with AttachmentIdList in interfaces.

sync/internal_api/public/read_transaction.h

 // Copyright 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_READ_TRANSACTION_H_
 #define SYNC_INTERNAL_API_PUBLIC_READ_TRANSACTION_H_
 
 #include "base/compiler_specific.h"
 #include "sync/api/attachments/attachment_id.h"
 #include "sync/base/sync_export.h"
@@ skipping 28 matching lines @@
   syncable::BaseTransaction* GetWrappedTrans() const override;
 
   // Return |transaction_version| of |type| stored in sync directory's
   // persisted info.
   int64 GetModelVersion(ModelType type) const;
 
   // Fills |context| with the datatype context associated with |type|.
   void GetDataTypeContext(ModelType type,
                           sync_pb::DataTypeContext* context) const;
 
-  // Clear |id_set| and fill it with the ids of attachments that need to be
+  // Clear |ids| and fill it with the ids of attachments that need to be
   // uploaded to the sync server.
-  void GetAttachmentIdsToUpload(ModelType type, AttachmentIdSet* id_set) const;
+  void GetAttachmentIdsToUpload(ModelType type, AttachmentIdList* ids) const;
 
   // Return the current (opaque) store birthday.
   std::string GetStoreBirthday() const;
 
  private:
   void* operator new(size_t size);  // Transaction is meant for stack use only.
 
   // The underlying syncable object which this class wraps.
   syncable::BaseTransaction* transaction_;
   bool close_transaction_;
 
   DISALLOW_COPY_AND_ASSIGN(ReadTransaction);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_READ_TRANSACTION_H_