Split up SyncEngineEventListener callbacks

sync/engine/sync_engine_event.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_ENGINE_SYNC_ENGINE_EVENT_H_
-#define SYNC_ENGINE_SYNC_ENGINE_EVENT_H_
-
-#include <string>
-
-#include "base/observer_list.h"
-#include "sync/base/sync_export.h"
-#include "sync/internal_api/public/sessions/sync_session_snapshot.h"
-
-namespace syncable {
-class Id;
-}
-
-namespace syncer {
-
-struct SYNC_EXPORT_PRIVATE SyncEngineEvent {
-  enum EventCause {
-    ////////////////////////////////////////////////////////////////
-    // Sent on entry of Syncer state machine
-    SYNC_CYCLE_BEGIN,
-
-    // Sent any time progress is made during a sync cycle.
-    STATUS_CHANGED,
-
-    // We have reached the SYNCER_END state in the main sync loop.
-    SYNC_CYCLE_ENDED,
-
-    ////////////////////////////////////////////////////////////////
-    // Generated in response to specific protocol actions or events.
-
-    // This is sent after the Syncer (and SyncerThread) have initiated self
-    // halt due to no longer being permitted to communicate with the server.
-    // The listener should sever the sync / browser connections and delete sync
-    // data (i.e. as if the user clicked 'Stop Syncing' in the browser.
-    STOP_SYNCING_PERMANENTLY,
-
-    // This event is sent when we receive an actionable error. It is upto
-    // the listeners to figure out the action to take using the snapshot sent.
-    ACTIONABLE_ERROR,
-
-    // This event is sent when scheduler decides to wait before next request
-    // either because it gets throttled by server or because it backs off after
-    // request failure. Retry time is passed in retry_time field of event.
-    RETRY_TIME_CHANGED,
-
-    // This event is sent when types are throttled or unthrottled.
-    THROTTLED_TYPES_CHANGED,
-  };
-
-  explicit SyncEngineEvent(EventCause cause);
-  ~SyncEngineEvent();
-
-  EventCause what_happened;
-
-  // The last session used for syncing.
-  sessions::SyncSessionSnapshot snapshot;
-
-  // Update-Client-Auth returns a new token for sync use.
-  std::string updated_token;
-
-  // Time when scheduler will try to send request after backoff.
-  base::Time retry_time;
-
-  // Set of types that are currently throttled.
-  ModelTypeSet throttled_types;
-};
-
-class SYNC_EXPORT_PRIVATE SyncEngineEventListener {
- public:
-  // TODO(tim): Consider splitting this up to multiple callbacks, rather than
-  // have to do Event e(type); OnSyncEngineEvent(e); at all callsites,
-  virtual void OnSyncEngineEvent(const SyncEngineEvent& event) = 0;
- protected:
-  virtual ~SyncEngineEventListener() {}
-};
-
-}  // namespace syncer
-
-#endif  // SYNC_ENGINE_SYNC_ENGINE_EVENT_H_