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diff --git a/third_party/libwebrtc/modules/video_coding/utility/decoded_frames_history.h b/third_party/libwebrtc/modules/video_coding/utility/decoded_frames_history.h
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+/*
+ *  Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef MODULES_VIDEO_CODING_UTILITY_DECODED_FRAMES_HISTORY_H_
+#define MODULES_VIDEO_CODING_UTILITY_DECODED_FRAMES_HISTORY_H_
+
+#include <stdint.h>
+
+#include <bitset>
+#include <vector>
+
+#include "absl/types/optional.h"
+#include "api/video/encoded_frame.h"
+
+namespace webrtc {
+namespace video_coding {
+
+class DecodedFramesHistory {
+ public:
+  // window_size - how much frames back to the past are actually remembered.
+  explicit DecodedFramesHistory(size_t window_size);
+  ~DecodedFramesHistory();
+  // Called for each decoded frame. Assumes frame id's are non-decreasing.
+  void InsertDecoded(int64_t frame_id, uint32_t timestamp);
+  // Query if the following (frame_id, spatial_id) pair was inserted before.
+  // Should be at most less by window_size-1 than the last inserted frame id.
+  bool WasDecoded(int64_t frame_id) const;
+
+  void Clear();
+
+  absl::optional<int64_t> GetLastDecodedFrameId() const;
+  absl::optional<uint32_t> GetLastDecodedFrameTimestamp() const;
+
+ private:
+  int FrameIdToIndex(int64_t frame_id) const;
+
+  std::vector<bool> buffer_;
+  absl::optional<int64_t> last_frame_id_;
+  absl::optional<int64_t> last_decoded_frame_;
+  absl::optional<uint32_t> last_decoded_frame_timestamp_;
+};
+
+}  // namespace video_coding
+}  // namespace webrtc
+#endif  // MODULES_VIDEO_CODING_UTILITY_DECODED_FRAMES_HISTORY_H_