Introduce a layering in the invalidation component as public and impl

components/invalidation/invalidation_state_tracker.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.
-//
-// An InvalidationStateTracker is an interface that handles persisting state
-// needed for invalidations. Currently, it is responsible for managing the
-// following information:
-// - Max version seen from the invalidation server to help dedupe invalidations.
-// - Bootstrap data for the invalidation client.
-// - Payloads and locally generated ack handles, to support local acking.
-
-#ifndef COMPONENTS_INVALIDATION_INVALIDATION_STATE_TRACKER_H_
-#define COMPONENTS_INVALIDATION_INVALIDATION_STATE_TRACKER_H_
-
-#include <map>
-#include <string>
-
-#include "base/basictypes.h"
-#include "base/callback_forward.h"
-#include "base/memory/ref_counted.h"
-#include "components/invalidation/invalidation.h"
-#include "components/invalidation/invalidation_export.h"
-#include "components/invalidation/invalidation_util.h"
-#include "components/invalidation/unacked_invalidation_set.h"
-#include "google/cacheinvalidation/include/types.h"
-
-namespace base {
-class TaskRunner;
-}  // namespace base
-
-namespace syncer {
-
-class INVALIDATION_EXPORT InvalidationStateTracker {
- public:
-  InvalidationStateTracker();
-  virtual ~InvalidationStateTracker();
-
-  // The per-client unique ID used to register the invalidation client with the
-  // server.  This is used to squelch invalidation notifications that originate
-  // from changes made by this client.  Setting the client ID clears all other
-  // state.
-  virtual void ClearAndSetNewClientId(const std::string& data) = 0;
-  virtual std::string GetInvalidatorClientId() const = 0;
-
-  // Used by invalidation::InvalidationClient for persistence. |data| is an
-  // opaque blob that an invalidation client can use after a restart to
-  // bootstrap itself. |data| is binary data (not valid UTF8, embedded nulls,
-  // etc).
-  virtual void SetBootstrapData(const std::string& data) = 0;
-  virtual std::string GetBootstrapData() const = 0;
-
-  // Used to store invalidations that have been acked to the server, but not yet
-  // handled by our clients.  We store these invalidations on disk so we won't
-  // lose them if we need to restart.
-  virtual void SetSavedInvalidations(const UnackedInvalidationsMap& states) = 0;
-  virtual UnackedInvalidationsMap GetSavedInvalidations() const = 0;
-
-  // Erases invalidation versions, client ID, and state stored on disk.
-  virtual void Clear() = 0;
-};
-
-}  // namespace syncer
-
-#endif  // COMPONENTS_INVALIDATION_INVALIDATION_STATE_TRACKER_H_