diff --git a/buffet/states/state_change_queue.h b/buffet/states/state_change_queue.h
new file mode 100644
index 0000000..a5cde95
--- /dev/null
+++ b/buffet/states/state_change_queue.h
@@ -0,0 +1,45 @@
+// Copyright 2014 The Chromium OS 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 BUFFET_STATES_STATE_CHANGE_QUEUE_H_
+#define BUFFET_STATES_STATE_CHANGE_QUEUE_H_
+
+#include <vector>
+
+#include <base/macros.h>
+#include <base/threading/thread_checker.h>
+
+#include "buffet/states/state_change_queue_interface.h"
+
+namespace buffet {
+
+// An object to record and retrieve device state change notification events.
+class StateChangeQueue : public StateChangeQueueInterface {
+ public:
+  explicit StateChangeQueue(size_t max_queue_size);
+
+  // Overrides from StateChangeQueueInterface.
+  bool IsEmpty() const override { return state_changes_.empty(); }
+  bool NotifyPropertiesUpdated(const StateChange& change) override;
+  std::vector<StateChange> GetAndClearRecordedStateChanges() override;
+
+ private:
+  // To make sure we do not call NotifyPropertiesUpdated() and
+  // GetAndClearRecordedStateChanges() on different threads, |thread_checker_|
+  // is here to help us with verifying the single-threaded operation.
+  base::ThreadChecker thread_checker_;
+
+  // Maximum queue size. If it is full, the oldest state update records are
+  // merged together until the queue size is within the size limit.
+  size_t max_queue_size_;
+
+  // Accumulated list of device state change notifications.
+  std::vector<StateChange> state_changes_;
+
+  DISALLOW_COPY_AND_ASSIGN(StateChangeQueue);
+};
+
+}  // namespace buffet
+
+#endif  // BUFFET_STATES_STATE_CHANGE_QUEUE_H_