Always use recvmmsg or recvmsg if it's available, and consolidate ReadAndDispatchPackets and ReadAn…

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 a4ba1be4c544113ad9483a6bae20990466f1f485..3f5f8c8c64c72ff5c49c33007bfee46884b8bd92 100644
--- a/net/tools/quic/quic_packet_reader.cc
+++ b/net/tools/quic/quic_packet_reader.cc
@@ -60,14 +60,24 @@ void QuicPacketReader::Initialize() {
 
 QuicPacketReader::~QuicPacketReader() {}
 
-// TODO(danzh): write a public method to wrap ReadAndDispatchPackets() and
-// ReadAndDispatchSinglePacket() based on MMSG_MORE.
 bool QuicPacketReader::ReadAndDispatchPackets(
     int fd,
     int port,
     ProcessPacketInterface* processor,
     QuicPacketCount* packets_dropped) {
 #if MMSG_MORE
+  return ReadAndDispatchManyPackets(fd, port, processor, packets_dropped);
+#else
+  return ReadAndDispatchSinglePacket(fd, port, processor, packets_dropped);
+#endif
+}
+
+bool QuicPacketReader::ReadAndDispatchManyPackets(
+    int fd,
+    int port,
+    ProcessPacketInterface* processor,
+    QuicPacketCount* packets_dropped) {
+#if MMSG_MORE
   // Re-set the length fields in case recvmmsg has changed them.
   for (int i = 0; i < kNumPacketsPerReadMmsgCall; ++i) {
     DCHECK_EQ(kMaxPacketSize, packets_[i].iov.iov_len);