Remove RED/RTX workaround from sender/receiver and VideoEngine2.

webrtc/modules/rtp_rtcp/source/rtp_payload_registry.cc

Index: webrtc/modules/rtp_rtcp/source/rtp_payload_registry.cc
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_payload_registry.cc b/webrtc/modules/rtp_rtcp/source/rtp_payload_registry.cc
index 283c2846e1bc8fbf70c8d7e90b4ad887412d8040..01a0234f5dbe09c96280417f10bb36d9baa2445e 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_payload_registry.cc
+++ b/webrtc/modules/rtp_rtcp/source/rtp_payload_registry.cc
@@ -23,7 +23,6 @@ RTPPayloadRegistry::RTPPayloadRegistry(RTPPayloadStrategy* rtp_payload_strategy)
       last_received_payload_type_(-1),
       last_received_media_payload_type_(-1),
       rtx_(false),
-      rtx_payload_type_(-1),
       ssrc_rtx_(0) {}
 
 RTPPayloadRegistry::~RTPPayloadRegistry() {
@@ -260,18 +259,14 @@ bool RTPPayloadRegistry::RestoreOriginalPacket(uint8_t* restored_packet,
 
   int associated_payload_type;

[danilchap, 2016/11/02 13:56:52]

might as well remove this variable and use apt_mapping->second directly now.

[brandtr, 2016/11/03 12:02:48]

Kept, because now I use it in multiple places.

   auto apt_mapping = rtx_payload_type_map_.find(header.payloadType);
-  if (apt_mapping == rtx_payload_type_map_.end())
+  if (apt_mapping == rtx_payload_type_map_.end()) {
+    LOG(LS_WARNING) << "No RTX associated payload type mapping was available; "

[danilchap, 2016/11/02 13:56:52]

Better to ensure you do not spam this messages (If there is an rtx packet with
mismatch payload_type, likely there will be a lot of them).

[brandtr, 2016/11/03 12:02:48]

Done.

+                       "not able to restore original packet from RTX packet "
+                       "with payload type: "
+                    << header.payloadType << ".";
     return false;
-  associated_payload_type = apt_mapping->second;
-  if (red_payload_type_ != -1) {
-    // Assume red will be used if it's configured.
-    // This is a workaround for a Chrome sdp bug where rtx is associated
-    // with the media codec even though media is sent over red.
-    // TODO(holmer): Remove once the Chrome versions exposing this bug are
-    // old enough, which should be once Chrome Stable reaches M53 as this
-    // work-around went into M50.
-    associated_payload_type = red_payload_type_;
   }
+  associated_payload_type = apt_mapping->second;
   restored_packet[1] = static_cast<uint8_t>(associated_payload_type);
   if (header.markerBit) {
     restored_packet[1] |= kRtpMarkerBitMask;  // Marker bit is set.
@@ -301,7 +296,6 @@ void RTPPayloadRegistry::SetRtxPayloadType(int payload_type,
 
   rtx_payload_type_map_[payload_type] = associated_payload_type;
   rtx_ = true;
-  rtx_payload_type_ = payload_type;
 }
 
 bool RTPPayloadRegistry::IsRed(const RTPHeader& header) const {