Split up SyncEngineEventListener callbacks

sync/engine/sync_engine_event_listener.h

Index: sync/engine/sync_engine_event_listener.h
diff --git a/sync/engine/sync_engine_event_listener.h b/sync/engine/sync_engine_event_listener.h
new file mode 100644
index 0000000000000000000000000000000000000000..2adffeb01a70f632f96aebbfaf7fa20099644710
--- /dev/null
+++ b/sync/engine/sync_engine_event_listener.h
@@ -0,0 +1,42 @@
+// 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_LISTENER_H_
+#define SYNC_ENGINE_SYNC_ENGINE_EVENT_LISTENER_H_
+
+#include "base/time/time.h"
+#include "sync/base/sync_export.h"
+#include "sync/internal_api/public/base/model_type.h"
+
+namespace syncer {
+
+struct SyncProtocolError;
+struct SyncCycleEvent;
+
+class SYNC_EXPORT_PRIVATE SyncEngineEventListener {
+ public:
+  SyncEngineEventListener();
+
+  // Generated at various points during the sync cycle.
+  virtual void OnSyncCycleEvent(const SyncCycleEvent& event) = 0;
+
+  // This event is sent when we receive an actionable error. It is up to
+  // the listeners to figure out the action to take using the error sent.
+  virtual void OnActionableError(const SyncProtocolError& error) = 0;
+
+  // 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.
+  virtual void OnRetryTimeChanged(base::Time retry_time) = 0;
+
+  // This event is sent when types are throttled or unthrottled.
+  virtual void OnThrottledTypesChanged(ModelTypeSet throttled_types) = 0;
+
+ protected:
+  virtual ~SyncEngineEventListener();
+};
+
+}  // namespace syncer
+
+#endif  // SYNC_ENGINE_SYNC_ENGINE_EVENT_LISTENER_H_