Update some callers to use more direct ways of constructing IPAddress from well known literals.

net/quic/test_tools/quic_test_utils.cc

 // Copyright (c) 2012 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/quic/test_tools/quic_test_utils.h"
 
 #include "base/sha1.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "net/quic/crypto/crypto_framer.h"
@@ skipping 438 matching lines @@
 
 QuicVersion QuicVersionMax() {
   return QuicSupportedVersions().front();
 }
 
 QuicVersion QuicVersionMin() {
   return QuicSupportedVersions().back();
 }
 
 IPAddress Loopback4() {
-  return IPAddress(127, 0, 0, 1);
+  return IPAddress::IPv4Localhost();
 }
 
 IPAddress Loopback6() {
-  IPAddress addr;
-  CHECK(addr.AssignFromIPLiteral("::1"));
-  return addr;
+  return IPAddress::IPv6Localhost();
 }
 
 IPAddress Any4() {
-  return IPAddress(0, 0, 0, 0);
+  return IPAddress::IPv4AllZeros();
 }
 
 void GenerateBody(string* body, int length) {
   body->clear();
   body->reserve(length);
   for (int i = 0; i < length; ++i) {
     body->append(1, static_cast<char>(32 + i % (126 - 32)));
   }
 }
 
@@ skipping 317 matching lines @@
   // strike register worries that we've just overflowed a uint32_t time.
   (*server_connection)->AdvanceTime(connection_start_time);
 }
 
 QuicStreamId QuicClientDataStreamId(int i) {
   return kClientDataStreamId1 + 2 * i;
 }
 
 }  // namespace test
 }  // namespace net