Deprecate FLAGS_quic_read_packets_full_recvmmsg.

net/tools/quic/quic_packet_reader.cc

Index: net/tools/quic/quic_packet_reader.cc
diff --git a/net/tools/quic/quic_packet_reader.cc b/net/tools/quic/quic_packet_reader.cc
index 1f368a683dca28d44660eb32ae83a63d982642dc..90f058708ca22807ff354c074bfc9618747ba3b6 100644
--- a/net/tools/quic/quic_packet_reader.cc
+++ b/net/tools/quic/quic_packet_reader.cc
@@ -104,12 +104,8 @@ bool QuicPacketReader::ReadAndDispatchPackets(
                                            packets_dropped);
   }
 
-  if (FLAGS_quic_read_packets_full_recvmmsg) {
-    // We may not have read all of the packets available on the socket.
-    return packets_read == kNumPacketsPerReadMmsgCall;
-  } else {
-    return true;
-  }
+  // We may not have read all of the packets available on the socket.
+  return packets_read == kNumPacketsPerReadMmsgCall;
 #else
   LOG(FATAL) << "Unsupported";
   return false;