Remove dead code

webrtc/modules/audio_coding/codecs/isac/audio_encoder_isac_t.h

Index: webrtc/modules/audio_coding/codecs/isac/audio_encoder_isac_t.h
diff --git a/webrtc/modules/audio_coding/codecs/isac/audio_encoder_isac_t.h b/webrtc/modules/audio_coding/codecs/isac/audio_encoder_isac_t.h
index 2cc23db9fea0f10baa63bedc4a306639bf48c828..c12d734f7c13782dda4b2ef2c516b4e1ecbe0d93 100644
--- a/webrtc/modules/audio_coding/codecs/isac/audio_encoder_isac_t.h
+++ b/webrtc/modules/audio_coding/codecs/isac/audio_encoder_isac_t.h
@@ -14,7 +14,6 @@
 #include <vector>
 
 #include "webrtc/api/audio_codecs/audio_encoder.h"
-#include "webrtc/api/audio_codecs/audio_format.h"
 #include "webrtc/modules/audio_coding/codecs/isac/locked_bandwidth_info.h"
 #include "webrtc/rtc_base/constructormagic.h"
 #include "webrtc/rtc_base/scoped_ref_ptr.h"
@@ -56,13 +55,8 @@ class AudioEncoderIsacT final : public AudioEncoder {
   explicit AudioEncoderIsacT(
       const CodecInst& codec_inst,
       const rtc::scoped_refptr<LockedIsacBandwidthInfo>& bwinfo);
-  AudioEncoderIsacT(int payload_type, const SdpAudioFormat& format);
   ~AudioEncoderIsacT() override;
 
-  static constexpr const char* GetPayloadName() { return "ISAC"; }
-  static rtc::Optional<AudioCodecInfo> QueryAudioEncoder(
-      const SdpAudioFormat& format);
-
   int SampleRateHz() const override;
   size_t NumChannels() const override;
   size_t Num10MsFramesInNextPacket() const override;