Add quic_test_loopback used for tests only.

net/tools/quic/quic_server_test.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/tools/quic/quic_server.h"
 
 #include "net/quic/core/crypto/quic_random.h"
 #include "net/quic/core/quic_utils.h"
 #include "net/quic/platform/api/quic_flags.h"
 #include "net/quic/platform/api/quic_logging.h"
 #include "net/quic/platform/api/quic_socket_address.h"
 #include "net/quic/platform/api/quic_test.h"
+#include "net/quic/platform/api/quic_test_loopback.h"
 #include "net/quic/test_tools/crypto_test_utils.h"
 #include "net/quic/test_tools/mock_quic_dispatcher.h"
 #include "net/tools/quic/quic_epoll_alarm_factory.h"
 #include "net/tools/quic/quic_epoll_connection_helper.h"
 #include "net/tools/quic/quic_simple_crypto_server_stream_helper.h"
 #include "net/tools/quic/test_tools/quic_server_peer.h"
 
 using ::testing::_;
 
 namespace net {
@@ skipping 94 matching lines @@
   EXPECT_CALL(*dispatcher_, ProcessBufferedChlos(_)).Times(2);
   EXPECT_CALL(*dispatcher_, HasPendingWrites()).Times(testing::AnyNumber());
   // Expect there are still CHLOs buffered after 1st event. But not any more
   // after 2nd event.
   EXPECT_CALL(*dispatcher_, HasChlosBuffered())
       .WillOnce(testing::Return(true))
       .WillOnce(
           DoAll(testing::Assign(&more_chlos, false), testing::Return(false)));
 
   // Send a packet to trigger epoll event.
-  int fd = socket(AF_INET, SOCK_DGRAM | SOCK_NONBLOCK, IPPROTO_UDP);
+  int fd = socket(
+      AddressFamilyUnderTest() == IpAddressFamily::IP_V4 ? AF_INET : AF_INET6,
+      SOCK_DGRAM | SOCK_NONBLOCK, IPPROTO_UDP);
   ASSERT_LT(0, fd);
 
   char buf[1024];
   memset(buf, 0, arraysize(buf));
   sockaddr_storage storage = server_address_.generic_address();
   int rc = sendto(fd, buf, arraysize(buf), 0,
                   reinterpret_cast<sockaddr*>(&storage), sizeof(storage));
   if (rc < 0) {
     QUIC_DLOG(INFO) << errno << " " << strerror(errno);
   }
@@ skipping 59 matching lines @@
       reinterpret_cast<char*>(valid_packet), arraysize(valid_packet),
       QuicTime::Zero(), false);
 
   EXPECT_CALL(dispatcher_, ProcessPacket(_, _, _)).Times(1);
   DispatchPacket(encrypted_valid_packet);
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace net