base: Get rid of 'using' declaration of StringAppendF.

net/http/http_util.cc

 // Copyright (c) 2010 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.
 
 // The rules for parsing content-types were borrowed from Firefox:
 // http://lxr.mozilla.org/mozilla/source/netwerk/base/src/nsURLHelper.cpp#834
 
 #include "net/http/http_util.h"
 
 #include <algorithm>
@@ skipping 572 matching lines @@
   unsigned int qvalue10 = 10;
   StringTokenizer t(raw_language_list, ",");
   std::string lang_list_with_q;
   while (t.GetNext()) {
     std::string language = t.token();
     if (qvalue10 == 10) {
       // q=1.0 is implicit.
       lang_list_with_q = language;
     } else {
       DCHECK_LT(qvalue10, 10U);
-      StringAppendF(&lang_list_with_q, ",%s;q=0.%d", language.c_str(),
-                    qvalue10);
+      base::StringAppendF(&lang_list_with_q, ",%s;q=0.%d", language.c_str(),
+                          qvalue10);
     }
     // It does not make sense to have 'q=0'.
     if (qvalue10 > kQvalueDecrement10)
       qvalue10 -= kQvalueDecrement10;
   }
   return lang_list_with_q;
 }
 
 std::string HttpUtil::GenerateAcceptCharsetHeader(const std::string& charset) {
   std::string charset_with_q = charset;
@@ skipping 256 matching lines @@
       value_is_quoted_ = true;
       // Do not store iterators into this. See declaration of unquoted_value_.
       unquoted_value_ = HttpUtil::Unquote(value_begin_, value_end_);
     }
   }
 
   return true;
 }
 
 }  // namespace net