Revert of Remove unnecessary interface TelephoneEventHandler

webrtc/modules/rtp_rtcp/source/rtp_receiver_strategy.h

Index: webrtc/modules/rtp_rtcp/source/rtp_receiver_strategy.h
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_receiver_strategy.h b/webrtc/modules/rtp_rtcp/source/rtp_receiver_strategy.h
index 02ec8f836aad26a91ad7d012028b17fea055e00b..663b883295d70e8f946e45f008700036a16da9a5 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_receiver_strategy.h
+++ b/webrtc/modules/rtp_rtcp/source/rtp_receiver_strategy.h
@@ -43,6 +43,8 @@
                                  size_t payload_length,
                                  int64_t timestamp_ms,
                                  bool is_first_packet) = 0;
+
+  virtual TelephoneEventHandler* GetTelephoneEventHandler() = 0;
 
   // Retrieves the last known applicable frequency.
   virtual int GetPayloadTypeFrequency() const = 0;