Remove QUIC_VERSION_15 now that Chrome Stable supports QUIC_VERSION_16.

net/quic/quic_framer.cc

Index: net/quic/quic_framer.cc
diff --git a/net/quic/quic_framer.cc b/net/quic/quic_framer.cc
index 1a648b85397d9737dddd6f018c66710758ba379f..e3a6bf1c783334d2fb04285d0b44a0c12ec1f9fc 100644
--- a/net/quic/quic_framer.cc
+++ b/net/quic/quic_framer.cc
@@ -198,12 +198,8 @@ size_t QuicFramer::GetMinAckFrameSize(
     QuicVersion version,
     QuicSequenceNumberLength sequence_number_length,
     QuicSequenceNumberLength largest_observed_length) {
-  size_t len = kQuicFrameTypeSize + kQuicEntropyHashSize +
+  return kQuicFrameTypeSize + kQuicEntropyHashSize +
       largest_observed_length + kQuicDeltaTimeLargestObservedSize;
-  if (version <= QUIC_VERSION_15) {
-    len += sequence_number_length + kQuicEntropyHashSize;
-  }
-  return len;
 }
 
 // static
@@ -382,11 +378,6 @@ SerializedPacket QuicFramer::BuildDataPacket(
         }
         break;
       case STOP_WAITING_FRAME:
-        if (quic_version_ <= QUIC_VERSION_15) {
-          LOG(DFATAL) << "Attempt to add a StopWaitingFrame in "
-                      << QuicVersionToString(quic_version_);
-          return kNoPacket;
-        }
         if (!AppendStopWaitingFrame(
                 header, *frame.stop_waiting_frame, &writer)) {
           LOG(DFATAL) << "AppendStopWaitingFrame failed";
@@ -1219,11 +1210,6 @@ bool QuicFramer::ProcessFrameData(const QuicPacketHeader& header) {
       }
 
       case STOP_WAITING_FRAME: {
-        if (quic_version_ <= QUIC_VERSION_15) {
-          LOG(DFATAL) << "Trying to read a StopWaiting in "
-                      << QuicVersionToString(quic_version_);
-          return RaiseError(QUIC_INTERNAL_ERROR);
-        }
         QuicStopWaitingFrame stop_waiting_frame;
         if (!ProcessStopWaitingFrame(header, &stop_waiting_frame)) {
           return RaiseError(QUIC_INVALID_STOP_WAITING_DATA);
@@ -1321,11 +1307,6 @@ bool QuicFramer::ProcessStreamFrame(uint8 frame_type,
 bool QuicFramer::ProcessAckFrame(const QuicPacketHeader& header,
                                  uint8 frame_type,
                                  QuicAckFrame* frame) {
-  if (quic_version_ <= QUIC_VERSION_15) {
-    if (!ProcessStopWaitingFrame(header, &frame->sent_info)) {
-      return false;
-    }
-  }
   if (!ProcessReceivedInfo(frame_type, &frame->received_info)) {
     return false;
   }
@@ -2049,12 +2030,6 @@ bool QuicFramer::AppendAckFrameAndTypeByte(
     return false;
   }
 
-  if (quic_version_ <= QUIC_VERSION_15) {
-    if (!AppendStopWaitingFrame(header, frame.sent_info, writer)) {
-      return false;
-    }
-  }
-
   const ReceivedPacketInfo& received_info = frame.received_info;
   QuicPacketEntropyHash ack_entropy_hash = received_info.entropy_hash;
   NackRangeMap::reverse_iterator ack_iter = ack_info.nack_ranges.rbegin();