Use a direct include of strings headers in chrome/browser/chromeos/.

chrome/browser/chromeos/login/mock_url_fetchers.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 "chrome/browser/chromeos/login/mock_url_fetchers.h"
 
 #include <errno.h>
 
 #include "base/bind.h"
 #include "base/message_loop.h"
-#include "base/stringprintf.h"
+#include "base/strings/stringprintf.h"
 #include "googleurl/src/gurl.h"
 #include "net/http/http_status_code.h"
 #include "net/url_request/url_fetcher.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "net/url_request/url_request_status.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace chromeos {
 
 ExpectCanceledFetcher::ExpectCanceledFetcher(
@@ skipping 141 matching lines @@
   VLOG(1) << upload_data();
   if (upload_data().find("HOSTED") == std::string::npos) {
     VLOG(1) << "HostedFetcher failing request";
     set_response_code(net::HTTP_FORBIDDEN);
     SetResponseString("Error=BadAuthentication");
   }
   delegate()->OnURLFetchComplete(this);
 }
 
 }  // namespace chromeos