Move all core files in //components/sessions into core/ subdir

components/sessions/base_session_service_delegate.h

-// Copyright 2014 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 COMPONENTS_SESSIONS_BASE_SESSION_SERVICE_DELEGATE_H_
-#define COMPONENTS_SESSIONS_BASE_SESSION_SERVICE_DELEGATE_H_
-
-#include "base/memory/scoped_ptr.h"
-
-namespace base {
-class SequencedWorkerPool;
-}
-
-namespace sessions {
-
-// The BaseSessionServiceDelegate decouples the BaseSessionService from
-// chrome/content dependencies.
-class BaseSessionServiceDelegate {
- public:
-  BaseSessionServiceDelegate() {}
-
-  // Get the sequenced worker pool for running tasks on the backend thread as
-  // long as the system is not shutting down.
-  virtual base::SequencedWorkerPool* GetBlockingPool() = 0;
-
-  // Returns true if save operations can be performed as a delayed task - which
-  // is usually only used by unit tests.
-  virtual bool ShouldUseDelayedSave() = 0;
-
-  // Called when commands are about to be written to disc.
-  virtual void OnWillSaveCommands() {}
-
-  // Called when commands were saved to disc.
-  virtual void OnSavedCommands() {}
-
- protected:
-  virtual ~BaseSessionServiceDelegate() {}
-};
-
-}  // namespace sessions
-
-#endif  // COMPONENTS_SESSIONS_BASE_SESSION_SERVICE_DELEGATE_H_