Remove parity tracking in FEC groups as part of the migration to

net/quic/quic_fec_group.cc

Index: net/quic/quic_fec_group.cc
diff --git a/net/quic/quic_fec_group.cc b/net/quic/quic_fec_group.cc
index 8e37044f51af57df3537df82ea4e619636c8e2f4..c2c65809616c7abdd8efd61917e3a81a6a837a87 100644
--- a/net/quic/quic_fec_group.cc
+++ b/net/quic/quic_fec_group.cc
@@ -22,8 +22,7 @@ const QuicPacketSequenceNumber kNoSequenceNumber = kuint64max;
 QuicFecGroup::QuicFecGroup()
     : min_protected_packet_(kNoSequenceNumber),
       max_protected_packet_(kNoSequenceNumber),
-      payload_parity_len_(0),
-      entropy_parity_(false) {
+      payload_parity_len_(0) {
 }
 
 QuicFecGroup::~QuicFecGroup() {}
@@ -41,7 +40,7 @@ bool QuicFecGroup::Update(const QuicPacketHeader& header,
                 << header.packet_sequence_number;
     return false;
   }
-  if (!UpdateParity(decrypted_payload, header.entropy_flag)) {
+  if (!UpdateParity(decrypted_payload)) {
     return false;
   }
   received_packets_.insert(header.packet_sequence_number);
@@ -50,21 +49,19 @@ bool QuicFecGroup::Update(const QuicPacketHeader& header,
 
 bool QuicFecGroup::UpdateFec(
     QuicPacketSequenceNumber fec_packet_sequence_number,
-    bool fec_packet_entropy,
     const QuicFecData& fec) {
   if (min_protected_packet_ != kNoSequenceNumber) {
     return false;
   }
   SequenceNumberSet::const_iterator it = received_packets_.begin();
   while (it != received_packets_.end()) {
-    if ((*it < fec.fec_group) ||
-        (*it >= fec_packet_sequence_number)) {
+    if ((*it < fec.fec_group) || (*it >= fec_packet_sequence_number)) {
       DLOG(ERROR) << "FEC group does not cover received packet: " << *it;
       return false;
     }
     ++it;
   }
-  if (!UpdateParity(fec.redundancy, fec_packet_entropy)) {
+  if (!UpdateParity(fec.redundancy)) {
     return false;
   }
   min_protected_packet_ = fec.fec_group;
@@ -110,7 +107,7 @@ size_t QuicFecGroup::Revive(QuicPacketHeader* header,
   }
 
   header->packet_sequence_number = missing;
-  header->entropy_flag = entropy_parity_;
+  header->entropy_flag = 0;  // Unknown entropy.
 
   received_packets_.insert(missing);
   return payload_parity_len_;
@@ -125,7 +122,7 @@ bool QuicFecGroup::ProtectsPacketsBefore(QuicPacketSequenceNumber num) const {
   return *received_packets_.begin() < num;
 }
 
-bool QuicFecGroup::UpdateParity(StringPiece payload, bool entropy) {
+bool QuicFecGroup::UpdateParity(StringPiece payload) {
   DCHECK_LE(payload.size(), kMaxPacketSize);
   if (payload.size() > kMaxPacketSize) {
     DLOG(ERROR) << "Illegal payload size: " << payload.size();
@@ -144,7 +141,6 @@ bool QuicFecGroup::UpdateParity(StringPiece payload, bool entropy) {
       memset(payload_parity_ + payload.size(), 0,
              kMaxPacketSize - payload.size());
     }
-    entropy_parity_ = entropy;
     return true;
   }
   // Update the parity by XORing in the data (padding with 0s if necessary).
@@ -152,8 +148,6 @@ bool QuicFecGroup::UpdateParity(StringPiece payload, bool entropy) {
     uint8 byte = i < payload.size() ? payload[i] : 0x00;
     payload_parity_[i] ^= byte;
   }
-  // xor of boolean values.
-  entropy_parity_ = (entropy_parity_ != entropy);
   return true;
 }