iwyu: Include stringprintf.h where appropriate, part 3.

net/http/http_transaction_unittest.cc

 // Copyright (c) 2011 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/http/http_transaction_unittest.h"
 
 #include <algorithm>
 
 #include "base/message_loop.h"
-#include "base/string_util.h"
+#include "base/stringprintf.h"
 #include "net/base/net_errors.h"
 #include "net/base/load_flags.h"
 #include "net/disk_cache/disk_cache.h"
 #include "net/http/http_cache.h"
 #include "net/http/http_request_info.h"
 #include "net/http/http_response_info.h"
 #include "net/http/http_transaction.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
@@ skipping 337 matching lines @@
     if (rv > 0) {
       content.append(buf->data(), rv);
     } else if (rv < 0) {
       return rv;
     }
   } while (rv > 0);
 
   result->swap(content);
   return net::OK;
 }