Use a direct include of strings headers in extensions/, google_apis/, gpu/.

google_apis/gaia/google_service_auth_error.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 "google_apis/gaia/google_service_auth_error.h"
 
 #include <string>
 
 #include "base/json/json_reader.h"
 #include "base/logging.h"
-#include "base/string_util.h"
-#include "base/stringprintf.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
 #include "base/values.h"
 #include "net/base/net_errors.h"
 
 GoogleServiceAuthError::Captcha::Captcha() : image_width(0), image_height(0) {
 }
 
 GoogleServiceAuthError::Captcha::Captcha(
     const std::string& token, const GURL& audio, const GURL& img,
     const GURL& unlock, int width, int height)
     : token(token), audio_url(audio), image_url(img), unlock_url(unlock),
@@ skipping 210 matching lines @@
 GoogleServiceAuthError::GoogleServiceAuthError(
     State s,
     const std::string& captcha_token,
     const std::string& prompt_text,
     const std::string& alternate_text,
     int field_length)
     : state_(s),
       second_factor_(captcha_token, prompt_text, alternate_text, field_length),
       network_error_(0) {
 }