Remove support for QUIC_VERSION_16.

net/quic/quic_connection.cc

Index: net/quic/quic_connection.cc
diff --git a/net/quic/quic_connection.cc b/net/quic/quic_connection.cc
index ea49a6c40198948dae6b9e64335f9514a1a34769..a190865ffdd51f5d58a7cace220977e5bac6f15d 100644
--- a/net/quic/quic_connection.cc
+++ b/net/quic/quic_connection.cc
@@ -1549,21 +1549,7 @@ void QuicConnection::SendPing() {
   if (retransmission_alarm_->IsSet()) {
     return;
   }
-  if (version() == QUIC_VERSION_16) {
-    // TODO(rch): remove this when we remove version 15 and 16.
-    // This is a horrible hideous hack which we should not support.
-    IOVector data;
-    char c_data[] = "C";
-    data.Append(c_data, 1);
-    QuicConsumedData consumed_data =
-        packet_generator_.ConsumeData(kCryptoStreamId, data, 0, false,
-                                      MAY_FEC_PROTECT, NULL);
-    if (consumed_data.bytes_consumed == 0) {
-      DLOG(ERROR) << "Unable to send ping!?";
-    }
-  } else {
-    packet_generator_.AddControlFrame(QuicFrame(new QuicPingFrame));
-  }
+  packet_generator_.AddControlFrame(QuicFrame(new QuicPingFrame));
 }
 
 void QuicConnection::SendAck() {