Refactor sync-specific parts out of SyncNotifier/SyncNotifierObserver

sync/notifier/invalidation_notifier_base.h

Index: sync/notifier/invalidation_notifier_base.h
diff --git a/sync/notifier/invalidation_notifier_base.h b/sync/notifier/invalidation_notifier_base.h
new file mode 100644
index 0000000000000000000000000000000000000000..71516e535b7db3272b5d6e055c33086913b269e6
--- /dev/null
+++ b/sync/notifier/invalidation_notifier_base.h
@@ -0,0 +1,56 @@
+// 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_NOTIFIER_INVALIDATION_NOTIFIER_BASE_H_
+#define SYNC_NOTIFIER_INVALIDATION_NOTIFIER_BASE_H_
+
+#include <map>
+
+#include "base/basictypes.h"
+#include "base/observer_list.h"
+#include "sync/notifier/invalidation_util.h"
+#include "sync/notifier/object_id_payload_map.h"
+#include "sync/notifier/sync_notifier.h"
+#include "sync/notifier/sync_notifier_observer.h"
+
+namespace syncer {
+
+// Logic shared between InvalidationNotifier and
+// NonBlockingInvalidationNotifier.
+class InvalidationNotifierBase : public SyncNotifier {
+ public:
+  InvalidationNotifierBase();
+  virtual ~InvalidationNotifierBase();
+
+  virtual void AddHandler(SyncNotifierObserver* observer) OVERRIDE;
+  virtual void RemoveHandler(SyncNotifierObserver* observer) OVERRIDE;
+
+ protected:
+  typedef std::map<invalidation::ObjectId,
+                   SyncNotifierObserver*,
+                   ObjectIdLessThan> ObjectIdObserverMap;
+
+  // Updates the mapping of object IDs to observers and returns all the keys,
+  // e.g. object IDs, that are currently in the map.
+  ObjectIdSet UpdateObjectIdObserverMap();
+
+  // Helper that sorts incoming invalidations into a bucket for each observer
+  // and then dispatches the batched invalidations to each respective observer.
+  void DispatchInvalidationsToObservers(const ObjectIdPayloadMap& id_payloads,
+                                        IncomingNotificationSource source);
+
+  // Note that this is non-const because FOR_EACH_OBSERVER() may mutate the
+  // original observer list.
+  ObserverList<SyncNotifierObserver>& observers() { return observers_; }
+
+ private:
+  ObserverList<SyncNotifierObserver> observers_;
+  ObjectIdObserverMap id_to_observer_map_;
+
+  DISALLOW_COPY_AND_ASSIGN(InvalidationNotifierBase);
+};
+
+}  // namespace syncer
+
+#endif  // SYNC_NOTIFIER_INVALIDATION_NOTIFIER_BASE_H_