Replace last remaining NULLs in gfe/quic with nullptr. No behavior change.

net/quic/crypto/quic_crypto_server_config_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/quic/crypto/quic_crypto_server_config.h"
 
 #include <stdarg.h>
 
 #include "base/stl_util.h"
 #include "net/quic/crypto/aes_128_gcm_12_encrypter.h"
@@ skipping 259 matching lines @@
         QuicCryptoServerConfig::GenerateConfig(rand_, &clock_, options));
     override_config_protobuf_->set_source_address_token_secret_override(
         "a secret key");
     // Lower priority than the default config.
     override_config_protobuf_->set_priority(1);
     override_config_.reset(
         server_.AddConfig(override_config_protobuf_.get(), original_time_));
   }
 
   string NewSourceAddressToken(string config_id, const IPAddressNumber& ip) {
-    return NewSourceAddressToken(config_id, ip, NULL);
+    return NewSourceAddressToken(config_id, ip, nullptr);
   }
 
   string NewSourceAddressToken(string config_id,
                                const IPAddressNumber& ip,
                                const SourceAddressTokens& previous_tokens) {
     return peer_.NewSourceAddressToken(config_id, previous_tokens, ip, rand_,
-                                       clock_.WallNow(), NULL);
+                                       clock_.WallNow(), nullptr);
   }
 
   string NewSourceAddressToken(string config_id,
                                const IPAddressNumber& ip,
                                CachedNetworkParameters* cached_network_params) {
     SourceAddressTokens previous_tokens;
     return peer_.NewSourceAddressToken(config_id, previous_tokens, ip, rand_,
                                        clock_.WallNow(), cached_network_params);
   }
 
   HandshakeFailureReason ValidateSourceAddressTokens(
       string config_id,
       StringPiece srct,
       const IPAddressNumber& ip) {
-    return ValidateSourceAddressTokens(config_id, srct, ip, NULL);
+    return ValidateSourceAddressTokens(config_id, srct, ip, nullptr);
   }
 
   HandshakeFailureReason ValidateSourceAddressTokens(
       string config_id,
       StringPiece srct,
       const IPAddressNumber& ip,
       CachedNetworkParameters* cached_network_params) {
     return peer_.ValidateSourceAddressTokens(
         config_id, srct, ip, clock_.WallNow(), cached_network_params);
   }
@@ skipping 445 matching lines @@
              nullptr);
   test_peer_.CheckConfigs(
       "a", false,
       "b", true,
       "c", false,
       nullptr);
 }
 
 }  // namespace test
 }  // namespace net