Add FlexfecReceiveStream.

webrtc/api/call/flexfec_receive_stream.h

+/*
+ *  Copyright (c) 2016 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 WEBRTC_API_CALL_FLEXFEC_RECEIVE_STREAM_H_
+#define WEBRTC_API_CALL_FLEXFEC_RECEIVE_STREAM_H_
+
+#include <string>
+
+#include "webrtc/config.h"
+
+namespace webrtc {
+
+// WORK IN PROGRESS!
+// This class is under development and it is not yet intended for use outside
+// of WebRTC.
+//
+// TODO(brandtr): Remove this comment when FlexFEC is ready for public use.
+
+class FlexfecReceiveStream {
+ public:
+  struct Stats {
+    std::string ToString(int64_t time_ms) const;
+
+    // TODO(brandtr): Add appropriate stats here.
+    int flexfec_bitrate_bps;
+  };
+
+  // TODO(brandtr): When we add multistream protection, and thus add a
+  // FlexfecSendStream class, remove FlexfecConfig from config.h and add
+  // the appropriate configs here and in FlexfecSendStream.
+  using Config = FlexfecConfig;
+
+  // Starts stream activity.
+  // When a stream is active, it can receive and process packets.
+  virtual void Start() = 0;
+  // Stops stream activity.
+  // When a stream is stopped, it can't receive nor process packets.
+  virtual void Stop() = 0;
+
+  virtual Stats GetStats() const = 0;
+
+ protected:
+  virtual ~FlexfecReceiveStream() = default;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_API_CALL_FLEXFEC_RECEIVE_STREAM_H_