Delete unused/unsupported RetransmissionMode constants

Configurability via SetSelectiveRetransmissions was deleted in
https://webrtc-review.googlesource.com/c/119920.

Delete constants kRetransmitFECPackets and kRetransmitAllPackets,
which are never enabled in production code. Also move the declaration
of RetransmissionMode from rtp_rtcp_defines.h to rtp_sender_video.h,
to reduce visibility to applications.

Bug: None
Change-Id: I70dcf7532aa3415a2449d8d807c500c1f149bf6d
Reviewed-on: https://webrtc-review.googlesource.com/c/120053
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26570}
diff --git a/modules/rtp_rtcp/include/rtp_rtcp_defines.h b/modules/rtp_rtcp/include/rtp_rtcp_defines.h
index cb1296d..1e80bb2 100644
--- a/modules/rtp_rtcp/include/rtp_rtcp_defines.h
+++ b/modules/rtp_rtcp/include/rtp_rtcp_defines.h
@@ -96,19 +96,6 @@
 
 enum RtpRtcpPacketType { kPacketRtp = 0, kPacketKeepAlive = 1 };
 
-// kConditionallyRetransmitHigherLayers allows retransmission of video frames
-// in higher layers if either the last frame in that layer was too far back in
-// time, or if we estimate that a new frame will be available in a lower layer
-// in a shorter time than it would take to request and receive a retransmission.
-enum RetransmissionMode : uint8_t {
-  kRetransmitOff = 0x0,
-  kRetransmitFECPackets = 0x1,
-  kRetransmitBaseLayer = 0x2,
-  kRetransmitHigherLayers = 0x4,
-  kConditionallyRetransmitHigherLayers = 0x8,
-  kRetransmitAllPackets = 0xFF
-};
-
 enum RtxMode {
   kRtxOff = 0x0,
   kRtxRetransmitted = 0x1,     // Only send retransmissions over RTX.
diff --git a/modules/rtp_rtcp/source/rtp_sender_unittest.cc b/modules/rtp_rtcp/source/rtp_sender_unittest.cc
index c421cf9..0529d89 100644
--- a/modules/rtp_rtcp/source/rtp_sender_unittest.cc
+++ b/modules/rtp_rtcp/source/rtp_sender_unittest.cc
@@ -1828,9 +1828,6 @@
             rtp_sender_video_->GetStorageType(
                 header, kConditionallyRetransmitHigherLayers,
                 kDefaultExpectedRetransmissionTimeMs));
-  EXPECT_EQ(kAllowRetransmission, rtp_sender_video_->GetStorageType(
-                                      header, kRetransmitAllPackets,
-                                      kDefaultExpectedRetransmissionTimeMs));
 }
 
 TEST_P(RtpSenderVideoTest, RetransmissionTypesH264) {
@@ -1852,9 +1849,6 @@
             rtp_sender_video_->GetStorageType(
                 header, kConditionallyRetransmitHigherLayers,
                 kDefaultExpectedRetransmissionTimeMs));
-  EXPECT_EQ(kAllowRetransmission, rtp_sender_video_->GetStorageType(
-                                      header, kRetransmitAllPackets,
-                                      kDefaultExpectedRetransmissionTimeMs));
 }
 
 TEST_P(RtpSenderVideoTest, RetransmissionTypesVP8BaseLayer) {
@@ -1884,9 +1878,6 @@
       rtp_sender_video_->GetStorageType(
           header, kRetransmitBaseLayer | kConditionallyRetransmitHigherLayers,
           kDefaultExpectedRetransmissionTimeMs));
-  EXPECT_EQ(kAllowRetransmission, rtp_sender_video_->GetStorageType(
-                                      header, kRetransmitAllPackets,
-                                      kDefaultExpectedRetransmissionTimeMs));
 }
 
 TEST_P(RtpSenderVideoTest, RetransmissionTypesVP8HigherLayers) {
@@ -1910,9 +1901,6 @@
               rtp_sender_video_->GetStorageType(
                   header, kRetransmitHigherLayers | kRetransmitBaseLayer,
                   kDefaultExpectedRetransmissionTimeMs));
-    EXPECT_EQ(kAllowRetransmission, rtp_sender_video_->GetStorageType(
-                                        header, kRetransmitAllPackets,
-                                        kDefaultExpectedRetransmissionTimeMs));
   }
 }
 
@@ -1937,9 +1925,6 @@
               rtp_sender_video_->GetStorageType(
                   header, kRetransmitHigherLayers | kRetransmitBaseLayer,
                   kDefaultExpectedRetransmissionTimeMs));
-    EXPECT_EQ(kAllowRetransmission, rtp_sender_video_->GetStorageType(
-                                        header, kRetransmitAllPackets,
-                                        kDefaultExpectedRetransmissionTimeMs));
   }
 }
 
diff --git a/modules/rtp_rtcp/source/rtp_sender_video.cc b/modules/rtp_rtcp/source/rtp_sender_video.cc
index 92805f3..949af14 100644
--- a/modules/rtp_rtcp/source/rtp_sender_video.cc
+++ b/modules/rtp_rtcp/source/rtp_sender_video.cc
@@ -227,7 +227,6 @@
   BuildRedPayload(*media_packet, red_packet.get());
 
   std::vector<std::unique_ptr<RedPacket>> fec_packets;
-  StorageType fec_storage = kDontRetransmit;
   {
     // Only protect while creating RED and FEC packets, not when sending.
     rtc::CritScope cs(&crit_);
@@ -245,8 +244,6 @@
         fec_packets = ulpfec_generator_.GetUlpfecPacketsAsRed(
             red_payload_type_, ulpfec_payload_type_, first_fec_sequence_number);
         RTC_DCHECK_EQ(num_fec_packets, fec_packets.size());
-        if (retransmission_settings_ & kRetransmitFECPackets)
-          fec_storage = kAllowRetransmission;
       }
     }
   }
@@ -268,7 +265,7 @@
     rtp_packet->set_capture_time_ms(media_packet->capture_time_ms());
     rtp_packet->set_is_fec(true);
     uint16_t fec_sequence_number = rtp_packet->SequenceNumber();
-    if (rtp_sender_->SendToNetwork(std::move(rtp_packet), fec_storage,
+    if (rtp_sender_->SendToNetwork(std::move(rtp_packet), kDontRetransmit,
                                    RtpPacketSender::kLowPriority)) {
       rtc::CritScope cs(&stats_crit_);
       fec_bitrate_.Update(fec_packet->length(), clock_->TimeInMilliseconds());
@@ -664,8 +661,6 @@
     int64_t expected_retransmission_time_ms) {
   if (retransmission_settings == kRetransmitOff)
     return StorageType::kDontRetransmit;
-  if (retransmission_settings == kRetransmitAllPackets)
-    return StorageType::kAllowRetransmission;
 
   rtc::CritScope cs(&stats_crit_);
   // Media packet storage.
diff --git a/modules/rtp_rtcp/source/rtp_sender_video.h b/modules/rtp_rtcp/source/rtp_sender_video.h
index bba549b..8e26206 100644
--- a/modules/rtp_rtcp/source/rtp_sender_video.h
+++ b/modules/rtp_rtcp/source/rtp_sender_video.h
@@ -35,6 +35,17 @@
 class RtpPacketizer;
 class RtpPacketToSend;
 
+// kConditionallyRetransmitHigherLayers allows retransmission of video frames
+// in higher layers if either the last frame in that layer was too far back in
+// time, or if we estimate that a new frame will be available in a lower layer
+// in a shorter time than it would take to request and receive a retransmission.
+enum RetransmissionMode : uint8_t {
+  kRetransmitOff = 0x0,
+  kRetransmitBaseLayer = 0x2,
+  kRetransmitHigherLayers = 0x4,
+  kConditionallyRetransmitHigherLayers = 0x8,
+};
+
 class RTPSenderVideo {
  public:
   static constexpr int64_t kTLRateWindowSizeMs = 2500;