Remove obsolete fields in quic_protocol and their current usage in QUIC. Reorders QuicAckFrame fie…

net/quic/quic_protocol.h

Index: net/quic/quic_protocol.h
diff --git a/net/quic/quic_protocol.h b/net/quic/quic_protocol.h
index 3c29220db5037d7f346bdf98b325bd33ed239a7e..3cef76da21341c87c752c2bed4fed0f91950605a 100644
--- a/net/quic/quic_protocol.h
+++ b/net/quic/quic_protocol.h
@@ -42,7 +42,6 @@ typedef uint32_t QuicStreamId;
 typedef uint64_t QuicStreamOffset;
 typedef uint64_t QuicPacketNumber;
 typedef uint8_t QuicPathId;
-typedef QuicPacketNumber QuicFecGroupNumber;
 typedef uint64_t QuicPublicResetNonceProof;
 typedef uint8_t QuicPacketEntropyHash;
 typedef uint32_t QuicHeaderId;
@@ -87,9 +86,6 @@ const QuicByteCount kDefaultSocketReceiveBuffer = 256 * 1024;
 // Smaller values are ignored.
 const QuicByteCount kMinSocketReceiveBuffer = 16 * 1024;
 
-// Fraction of the receive buffer that can be used for encrypted bytes.
-// Allows a 5% overhead for IP and UDP framing, as well as ack only packets.
-static const float kUsableRecieveBufferFraction = 0.95f;
 // Fraction of the receive buffer that can be used, based on conservative
 // estimates and testing on Linux.
 // An alternative to kUsableRecieveBufferFraction.
@@ -112,8 +108,6 @@ const size_t kQuicVersionSize = 4;
 const size_t kQuicPathIdSize = 1;
 // Number of bytes reserved for private flags in the packet header.
 const size_t kPrivateFlagsSize = 1;
-// Number of bytes reserved for FEC group in the packet header.
-const size_t kFecGroupSize = 1;
 
 // Signifies that the QuicPacket will contain version of the protocol.
 const bool kIncludeVersion = true;
@@ -277,11 +271,6 @@ enum QuicConnectionIdLength {
   PACKET_8BYTE_CONNECTION_ID = 8
 };
 
-enum InFecGroup {
-  NOT_IN_FEC_GROUP,
-  IN_FEC_GROUP,
-};
-
 enum QuicPacketNumberLength : int8_t {
   PACKET_1BYTE_PACKET_NUMBER = 1,
   PACKET_2BYTE_PACKET_NUMBER = 2,
@@ -707,10 +696,6 @@ enum QuicErrorCode {
   QUIC_LAST_ERROR = 91,
 };
 
-// Must be updated any time a QuicErrorCode is deprecated.
-const int kDeprecatedQuicErrorCount = 4;
-const int kActiveQuicErrorCount = QUIC_LAST_ERROR - kDeprecatedQuicErrorCount;
-
 typedef char DiversificationNonce[32];
 
 struct NET_EXPORT_PRIVATE QuicPacketPublicHeader {
@@ -750,8 +735,6 @@ struct NET_EXPORT_PRIVATE QuicPacketHeader {
   bool entropy_flag;
   QuicPacketEntropyHash entropy_hash;
   bool fec_flag;
-  InFecGroup is_in_fec_group;
-  QuicFecGroupNumber fec_group;
 };
 
 struct NET_EXPORT_PRIVATE QuicPublicResetPacket {
@@ -1017,16 +1000,6 @@ struct NET_EXPORT_PRIVATE QuicAckFrame {
   NET_EXPORT_PRIVATE friend std::ostream& operator<<(std::ostream& os,
                                                      const QuicAckFrame& s);
 
-  // Path which this ack belongs to.
-  QuicPathId path_id;
-
-  // Entropy hash of all packets up to largest observed not including missing
-  // packets.
-  QuicPacketEntropyHash entropy_hash;
-
-  // Whether the ack had to be truncated when sent.
-  bool is_truncated;
-
   // The highest packet number we've observed from the peer.
   //
   // In general, this should be the largest packet number we've received.  In
@@ -1047,6 +1020,16 @@ struct NET_EXPORT_PRIVATE QuicAckFrame {
   // Set of packets.
   PacketNumberQueue packets;
 
+  // Path which this ack belongs to.
+  QuicPathId path_id;
+
+  // Entropy hash of all packets up to largest observed not including missing
+  // packets.
+  QuicPacketEntropyHash entropy_hash;
+
+  // Whether the ack had to be truncated when sent.
+  bool is_truncated;
+
   // If true, |packets| express missing packets. Otherwise, |packets| express
   // received packets.
   bool missing;
@@ -1404,7 +1387,7 @@ struct NET_EXPORT_PRIVATE SerializedPacket {
   // -1: full padding to the end of a max-sized packet
   //  0: no padding
   //  otherwise: only pad up to num_padding_bytes bytes
-  int num_padding_bytes;
+  int16_t num_padding_bytes;
   QuicPathId path_id;
   QuicPacketNumber packet_number;
   QuicPacketNumberLength packet_number_length;
@@ -1412,9 +1395,9 @@ struct NET_EXPORT_PRIVATE SerializedPacket {
   QuicPacketEntropyHash entropy_hash;
   bool has_ack;
   bool has_stop_waiting;
+  TransmissionType transmission_type;
   QuicPathId original_path_id;
   QuicPacketNumber original_packet_number;
-  TransmissionType transmission_type;
 
   // Optional notifiers which will be informed when this packet has been ACKed.
   std::list<AckListenerWrapper> listeners;
@@ -1454,7 +1437,7 @@ struct NET_EXPORT_PRIVATE TransmissionInfo {
   // True if the packet contains stream data from the crypto stream.
   bool has_crypto_handshake;
   // Non-zero if the packet needs padding if it's retransmitted.
-  int num_padding_bytes;
+  int16_t num_padding_bytes;
   // Stores the packet number of the next retransmission of this packet.
   // Zero if the packet has not been retransmitted.
   QuicPacketNumber retransmission;