Add test which verifies that the RTP header extensions are set correctly for FEC packets.

webrtc/modules/rtp_rtcp/source/rtp_sender_video.cc

Index: webrtc/modules/rtp_rtcp/source/rtp_sender_video.cc
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_sender_video.cc b/webrtc/modules/rtp_rtcp/source/rtp_sender_video.cc
index 3e2a2b80343cfb9ee5f61747a0858967ac93a08a..bec3623656ec84bee36191c64ed4abe00f64c702 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_sender_video.cc
+++ b/webrtc/modules/rtp_rtcp/source/rtp_sender_video.cc
@@ -42,13 +42,13 @@ RTPSenderVideo::RTPSenderVideo(Clock* clock, RTPSenderInterface* rtpSender)
       _retransmissionSettings(kRetransmitBaseLayer),
 
       // Generic FEC
-      _fec(),
-      _fecEnabled(false),
-      _payloadTypeRED(-1),
-      _payloadTypeFEC(-1),
+      fec_(),
+      fec_enabled_(false),
+      red_payload_type_(-1),
+      fec_payload_type_(-1),
       delta_fec_params_(),
       key_fec_params_(),
-      producer_fec_(&_fec),
+      producer_fec_(&fec_),
       _fecOverheadRate(clock, NULL),
       _videoBitrate(clock, NULL) {
   memset(&delta_fec_params_, 0, sizeof(delta_fec_params_));
@@ -130,7 +130,7 @@ void RTPSenderVideo::SendVideoPacketAsRed(uint8_t* data_buffer,
     // Only protect while creating RED and FEC packets, not when sending.
     CriticalSectionScoped cs(crit_.get());
     red_packet.reset(producer_fec_.BuildRedPacket(
-        data_buffer, payload_length, rtp_header_length, _payloadTypeRED));
+        data_buffer, payload_length, rtp_header_length, red_payload_type_));
     if (protect) {
       producer_fec_.AddRtpPacketAndGenerateFec(data_buffer, payload_length,
                                                rtp_header_length);
@@ -140,7 +140,7 @@ void RTPSenderVideo::SendVideoPacketAsRed(uint8_t* data_buffer,
       next_fec_sequence_number =
           _rtpSender.AllocateSequenceNumber(num_fec_packets);
       fec_packets = producer_fec_.GetFecPackets(
-          _payloadTypeRED, _payloadTypeFEC, next_fec_sequence_number,
+          red_payload_type_, fec_payload_type_, next_fec_sequence_number,
           rtp_header_length);
       RTC_DCHECK_EQ(num_fec_packets, fec_packets.size());
       if (_retransmissionSettings & kRetransmitFECPackets)
@@ -180,9 +180,9 @@ void RTPSenderVideo::SetGenericFECStatus(const bool enable,
                                          const uint8_t payloadTypeRED,
                                          const uint8_t payloadTypeFEC) {
   CriticalSectionScoped cs(crit_.get());
-  _fecEnabled = enable;
-  _payloadTypeRED = payloadTypeRED;
-  _payloadTypeFEC = payloadTypeFEC;
+  fec_enabled_ = enable;
+  red_payload_type_ = payloadTypeRED;
+  fec_payload_type_ = payloadTypeFEC;
   memset(&delta_fec_params_, 0, sizeof(delta_fec_params_));
   memset(&key_fec_params_, 0, sizeof(key_fec_params_));
   delta_fec_params_.max_fec_frames = key_fec_params_.max_fec_frames = 1;
@@ -194,14 +194,14 @@ void RTPSenderVideo::GenericFECStatus(bool& enable,
                                       uint8_t& payloadTypeRED,
                                       uint8_t& payloadTypeFEC) const {
   CriticalSectionScoped cs(crit_.get());
-  enable = _fecEnabled;
-  payloadTypeRED = _payloadTypeRED;
-  payloadTypeFEC = _payloadTypeFEC;
+  enable = fec_enabled_;
+  payloadTypeRED = red_payload_type_;
+  payloadTypeFEC = fec_payload_type_;
 }
 
 size_t RTPSenderVideo::FECPacketOverhead() const {
   CriticalSectionScoped cs(crit_.get());
-  if (_fecEnabled) {
+  if (fec_enabled_) {
     // Overhead is FEC headers plus RED for FEC header plus anything in RTP
     // header beyond the 12 bytes base header (CSRC list, extensions...)
     // This reason for the header extensions to be included here is that
@@ -247,7 +247,7 @@ int32_t RTPSenderVideo::SendVideo(const RtpVideoCodecTypes videoType,
         frameType == kVideoFrameKey ? &key_fec_params_ : &delta_fec_params_;
     producer_fec_.SetFecParameters(fec_params, 0);
     storage = packetizer->GetStorageType(_retransmissionSettings);
-    fec_enabled = _fecEnabled;
+    fec_enabled = fec_enabled_;
   }
 
   // Register CVO rtp header extension at the first time when we receive a frame