Rewrite scoped_ptr<T>(NULL) to use the default ctor in net/.

net/dns/dns_transaction_unittest.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/dns/dns_transaction.h"
 
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/rand_util.h"
@@ skipping 312 matching lines @@
   scoped_ptr<DnsTransaction> transaction_;
   int expected_answer_count_;
   bool cancel_in_callback_;
   bool quit_in_callback_;
 
   bool completed_;
 };
 
 class DnsTransactionTest : public testing::Test {
  public:
-  DnsTransactionTest() : socket_factory_(NULL) {}
+  DnsTransactionTest() {}
 
   // Generates |nameservers| for DnsConfig.
   void ConfigureNumServers(unsigned num_servers) {
     CHECK_LE(num_servers, 255u);
     config_.nameservers.clear();
     IPAddressNumber dns_ip;
     {
       bool rv = ParseIPLiteralToNumber("192.168.1.0", &dns_ip);
       EXPECT_TRUE(rv);
     }
@@ skipping 592 matching lines @@
   config_.timeout = TestTimeouts::tiny_timeout();
   ConfigureFactory();
 
   TransactionHelper helper0(".", dns_protocol::kTypeA, ERR_INVALID_ARGUMENT);
   EXPECT_TRUE(helper0.Run(transaction_factory_.get()));
 }
 
 }  // namespace
 
 }  // namespace net