Remove RED support from WebRtcVoiceEngine/MediaChannel.

webrtc/audio/audio_send_stream.cc

Index: webrtc/audio/audio_send_stream.cc
diff --git a/webrtc/audio/audio_send_stream.cc b/webrtc/audio/audio_send_stream.cc
index e9659c67e8c48ecd3bf09369d27562322b1e5be3..9b1e2fe5d3eaf40216c046d1ee48bb1e6de03e54 100644
--- a/webrtc/audio/audio_send_stream.cc
+++ b/webrtc/audio/audio_send_stream.cc
@@ -50,7 +50,6 @@ std::string AudioSendStream::Config::ToString() const {
   ss << ", voe_channel_id: " << voe_channel_id;
   // TODO(solenberg): Encoder config.
   ss << ", cng_payload_type: " << cng_payload_type;
-  ss << ", red_payload_type: " << red_payload_type;
   ss << '}';
   return ss.str();
 }