Create skeleton of the rtcp transceiver.

RtcpTransceiver name reserved for thread-safe version that planned to
be wrapper of the RtcpTransceiverImpl

BUG=webrtc:8239

Change-Id: If8a3092eb1b8e4175e3efd23b52e1043cdabf19f
Reviewed-on: https://webrtc-review.googlesource.com/7920
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20414}

modules/rtp_rtcp/source/rtcp_transceiver_impl.h

@@ -0,0 +1,42 @@
+/*
+ *  Copyright (c) 2017 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_RTP_RTCP_SOURCE_RTCP_TRANSCEIVER_IMPL_H_
+#define MODULES_RTP_RTCP_SOURCE_RTCP_TRANSCEIVER_IMPL_H_
+
+#include <memory>
+#include <string>
+
+#include "api/array_view.h"
+#include "modules/rtp_rtcp/source/rtcp_transceiver_config.h"
+#include "rtc_base/constructormagic.h"
+
+namespace webrtc {
+//
+// Manage incoming and outgoing rtcp messages for multiple BUNDLED streams.
+//
+// This class is not thread-safe.
+class RtcpTransceiverImpl {
+ public:
+  explicit RtcpTransceiverImpl(const RtcpTransceiverConfig& config);
+  ~RtcpTransceiverImpl();
+
+  // Sends RTCP packets starting with a sender or receiver report.
+  void SendCompoundPacket();
+
+ private:
+  const RtcpTransceiverConfig config_;
+
+  RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(RtcpTransceiverImpl);
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_RTP_RTCP_SOURCE_RTCP_TRANSCEIVER_IMPL_H_