Revert of Delete Rtx-related methods from RTPPayloadRegistry.

webrtc/modules/rtp_rtcp/test/testAPI/test_api.cc

 /*
  *  Copyright (c) 2012 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.
  */
 
@@ skipping 144 matching lines @@
   module_->SetRtxSendStatus(kRtxRetransmitted);
   EXPECT_EQ(kRtxRetransmitted, module_->RtxSendStatus());
 
   module_->SetRtxSendStatus(kRtxOff);
   EXPECT_EQ(kRtxOff, module_->RtxSendStatus());
 
   module_->SetRtxSendStatus(kRtxRetransmitted);
   EXPECT_EQ(kRtxRetransmitted, module_->RtxSendStatus());
 }
 
+TEST_F(RtpRtcpAPITest, RtxReceiver) {
+  const uint32_t kRtxSsrc = 1;
+  const int kRtxPayloadType = 119;
+  const int kPayloadType = 100;
+  EXPECT_FALSE(rtp_payload_registry_->RtxEnabled());
+  rtp_payload_registry_->SetRtxSsrc(kRtxSsrc);
+  rtp_payload_registry_->SetRtxPayloadType(kRtxPayloadType, kPayloadType);
+  EXPECT_TRUE(rtp_payload_registry_->RtxEnabled());
+  RTPHeader rtx_header;
+  rtx_header.ssrc = kRtxSsrc;
+  rtx_header.payloadType = kRtxPayloadType;
+  EXPECT_TRUE(rtp_payload_registry_->IsRtx(rtx_header));
+  rtx_header.ssrc = 0;
+  EXPECT_FALSE(rtp_payload_registry_->IsRtx(rtx_header));
+  rtx_header.ssrc = kRtxSsrc;
+  rtx_header.payloadType = 0;
+  EXPECT_TRUE(rtp_payload_registry_->IsRtx(rtx_header));
+}
+
 }  // namespace webrtc