Revert of Remove unnecessary interface TelephoneEventHandler

webrtc/modules/rtp_rtcp/source/rtp_receiver_impl.h

 /*
  *  Copyright (c) 2013 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.
  */
 
@@ skipping 39 matching lines @@
   // Returns the last received timestamp.
   bool Timestamp(uint32_t* timestamp) const override;
   bool LastReceivedTimeMs(int64_t* receive_time_ms) const override;
 
   uint32_t SSRC() const override;
 
   int32_t CSRCs(uint32_t array_of_csrc[kRtpCsrcSize]) const override;
 
   int32_t Energy(uint8_t array_of_energy[kRtpCsrcSize]) const override;
 
+  TelephoneEventHandler* GetTelephoneEventHandler() override;
+
  private:
   bool HaveReceivedFrame() const;
 
   void CheckSSRCChanged(const RTPHeader& rtp_header);
   void CheckCSRC(const WebRtcRTPHeader& rtp_header);
   int32_t CheckPayloadChanged(const RTPHeader& rtp_header,
                               const int8_t first_payload_byte,
                               bool* is_red,
                               PayloadUnion* payload);
 
@@ skipping 11 matching lines @@
   uint32_t ssrc_;
   uint8_t num_csrcs_;
   uint32_t current_remote_csrc_[kRtpCsrcSize];
 
   uint32_t last_received_timestamp_;
   int64_t last_received_frame_time_ms_;
   uint16_t last_received_sequence_number_;
 };
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_RECEIVER_IMPL_H_