Revert of Add RtcpRttStats to AudioStream

webrtc/audio/audio_send_stream.h

Index: webrtc/audio/audio_send_stream.h
diff --git a/webrtc/audio/audio_send_stream.h b/webrtc/audio/audio_send_stream.h
index 0f980fa370614875364db5fdf25634d016c3adde..2e0b7aed584620aaddcdf6f8c92b3926389b73b9 100644
--- a/webrtc/audio/audio_send_stream.h
+++ b/webrtc/audio/audio_send_stream.h
@@ -23,7 +23,6 @@
 class CongestionController;
 class VoiceEngine;
 class RtcEventLog;
-class RtcpRttStats;
 
 namespace voe {
 class ChannelProxy;
@@ -38,8 +37,7 @@
                   rtc::TaskQueue* worker_queue,
                   CongestionController* congestion_controller,
                   BitrateAllocator* bitrate_allocator,
-                  RtcEventLog* event_log,
-                  RtcpRttStats* rtcp_rtt_stats);
+                  RtcEventLog* event_log);
   ~AudioSendStream() override;
 
   // webrtc::AudioSendStream implementation.