Use a direct include of strings headers in cloud_print/.

cloud_print/service/service_state.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 "cloud_print/service/service_state.h"
 
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "net/base/escape.h"
 #include "net/base/io_buffer.h"
 #include "net/base/load_flags.h"
 #include "net/base/upload_bytes_element_reader.h"
 #include "net/base/upload_data_stream.h"
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_builder.h"
 
@@ skipping 191 matching lines @@
                              const std::string& password,
                              const std::string& proxy_id) {
   robot_token_.clear();
   robot_email_.clear();
   email_ = email;
   proxy_id_ = proxy_id;
   auth_token_ = LoginToGoogle("cloudprint", email_, password);
   xmpp_auth_token_ = LoginToGoogle("chromiumsync", email_, password);
   return IsValid();
 }