sync: Remove ClearUserData command.

sync/engine/clear_data_command.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_ENGINE_CLEAR_DATA_COMMAND_H_
-#define SYNC_ENGINE_CLEAR_DATA_COMMAND_H_
-#pragma once
-
-#include "base/basictypes.h"
-#include "sync/engine/syncer_command.h"
-#include "sync/internal_api/public/engine/model_safe_worker.h"
-#include "sync/internal_api/public/syncable/model_type.h"
-
-namespace browser_sync {
-
-// Clears server data associated with this user's account
-class ClearDataCommand : public SyncerCommand {
- public:
-  ClearDataCommand();
-  virtual ~ClearDataCommand();
-
-  // SyncerCommand implementation.
-  virtual SyncerError ExecuteImpl(sessions::SyncSession* session) OVERRIDE;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(ClearDataCommand);
-};
-
-}  // namespace browser_sync
-
-#endif  // SYNC_ENGINE_CLEAR_DATA_COMMAND_H_