diff --git a/pc/BUILD.gn b/pc/BUILD.gn
index fab96326cf..2763f85599 100644
--- a/pc/BUILD.gn
+++ b/pc/BUILD.gn
@@ -55,7 +55,6 @@ rtc_static_library("rtc_pc_base") {
     "rtp_transport.cc",
     "rtp_transport.h",
     "rtp_transport_internal.h",
-    "rtp_transport_internal_adapter.h",
     "session_description.cc",
     "session_description.h",
     "simulcast_description.cc",
diff --git a/pc/rtp_transport_internal_adapter.h b/pc/rtp_transport_internal_adapter.h
deleted file mode 100644
index c8fa8cc012..0000000000
--- a/pc/rtp_transport_internal_adapter.h
+++ /dev/null
@@ -1,114 +0,0 @@
-/*
- *  Copyright 2017 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.
- */
-
-#ifndef PC_RTP_TRANSPORT_INTERNAL_ADAPTER_H_
-#define PC_RTP_TRANSPORT_INTERNAL_ADAPTER_H_
-
-#include <memory>
-#include <utility>
-
-#include "pc/rtp_transport_internal.h"
-
-namespace webrtc {
-
-// This class is used by SrtpTransport and DtlsSrtpTransport in order to reduce
-// the duplicated code. Using this class, different subclasses can override only
-// part of RtpTransportInternal methods without implementing all the common
-// methods.
-class RtpTransportInternalAdapter : public RtpTransportInternal {
- public:
-  RtpTransportInternalAdapter() {}
-
-  explicit RtpTransportInternalAdapter(RtpTransportInternal* transport)
-      : transport_(transport) {
-    RTC_DCHECK(transport_);
-  }
-
-  void SetRtcpMuxEnabled(bool enable) override {
-    transport_->SetRtcpMuxEnabled(enable);
-  }
-
-  bool rtcp_mux_enabled() const override {
-    return transport_->rtcp_mux_enabled();
-  }
-
-  rtc::PacketTransportInternal* rtp_packet_transport() const override {
-    return transport_->rtp_packet_transport();
-  }
-  void SetRtpPacketTransport(rtc::PacketTransportInternal* rtp) override {
-    transport_->SetRtpPacketTransport(rtp);
-  }
-
-  rtc::PacketTransportInternal* rtcp_packet_transport() const override {
-    return transport_->rtcp_packet_transport();
-  }
-  void SetRtcpPacketTransport(rtc::PacketTransportInternal* rtcp) override {
-    transport_->SetRtcpPacketTransport(rtcp);
-  }
-
-  bool IsReadyToSend() const override { return transport_->IsReadyToSend(); }
-
-  bool IsWritable(bool rtcp) const override {
-    return transport_->IsWritable(rtcp);
-  }
-
-  bool SendRtpPacket(rtc::CopyOnWriteBuffer* packet,
-                     const rtc::PacketOptions& options,
-                     int flags) override {
-    return transport_->SendRtpPacket(packet, options, flags);
-  }
-
-  bool SendRtcpPacket(rtc::CopyOnWriteBuffer* packet,
-                      const rtc::PacketOptions& options,
-                      int flags) override {
-    return transport_->SendRtcpPacket(packet, options, flags);
-  }
-
-  void UpdateRtpHeaderExtensionMap(
-      const cricket::RtpHeaderExtensions& header_extensions) override {
-    transport_->UpdateRtpHeaderExtensionMap(header_extensions);
-  }
-
-  bool RegisterRtpDemuxerSink(const RtpDemuxerCriteria& criteria,
-                              RtpPacketSinkInterface* sink) override {
-    return transport_->RegisterRtpDemuxerSink(criteria, sink);
-  }
-
-  bool UnregisterRtpDemuxerSink(RtpPacketSinkInterface* sink) override {
-    return transport_->UnregisterRtpDemuxerSink(sink);
-  }
-
-  // RtpTransportInterface overrides.
-  PacketTransportInterface* GetRtpPacketTransport() const override {
-    return transport_->GetRtpPacketTransport();
-  }
-
-  PacketTransportInterface* GetRtcpPacketTransport() const override {
-    return transport_->GetRtcpPacketTransport();
-  }
-
-  RTCError SetParameters(const RtpTransportParameters& parameters) override {
-    return transport_->SetParameters(parameters);
-  }
-
-  RtpTransportParameters GetParameters() const override {
-    return transport_->GetParameters();
-  }
-
-  RtpTransportAdapter* GetInternal() override { return nullptr; }
-
- protected:
-  // Owned by the subclasses.
-  RtpTransportInternal* transport_ = nullptr;
-};
-
-}  // namespace webrtc
-
-#endif  // PC_RTP_TRANSPORT_INTERNAL_ADAPTER_H_