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

net/http/http_request_headers.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.
 
 #include "net/http/http_request_headers.h"
 
 #include "base/logging.h"
 #include "base/string_split.h"
 #include "base/string_util.h"
 #include "net/http/http_util.h"
@@ skipping 142 matching lines @@
   for (HeaderVector::const_iterator it = other.headers_.begin();
        it != other.headers_.end(); ++it ) {
     SetHeader(it->key, it->value);
   }
 }
 
 std::string HttpRequestHeaders::ToString() const {
   std::string output;
   for (HeaderVector::const_iterator it = headers_.begin();
        it != headers_.end(); ++it) {
-    if (!it->value.empty())
-      StringAppendF(&output, "%s: %s\r\n", it->key.c_str(), it->value.c_str());
-    else
-      StringAppendF(&output, "%s:\r\n", it->key.c_str());
+    if (!it->value.empty()) {
+      base::StringAppendF(&output, "%s: %s\r\n",
+                          it->key.c_str(), it->value.c_str());
+    } else {
+      base::StringAppendF(&output, "%s:\r\n", it->key.c_str());
+    }
   }
   output.append("\r\n");
   return output;
 }
 
 HttpRequestHeaders::HeaderVector::iterator
 HttpRequestHeaders::FindHeader(const base::StringPiece& key) {
   for (HeaderVector::iterator it = headers_.begin();
        it != headers_.end(); ++it) {
     if (key.length() == it->key.length() &&
@@ skipping 10 matching lines @@
        it != headers_.end(); ++it) {
     if (key.length() == it->key.length() &&
         !base::strncasecmp(key.data(), it->key.data(), key.length()))
       return it;
   }
 
   return headers_.end();
 }
 
 }  // namespace net