Use a direct include of strings headers in cloud_print/.

cloud_print/common/win/install_utils.h

 // Copyright 2013 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.
 
 #ifndef CLOUD_PRINT_COMMON_INSTALL_UTILS_H_
 #define CLOUD_PRINT_COMMON_INSTALL_UTILS_H_
 
 #include <wtypes.h>
 #include <string>
 
 #include "base/files/file_path.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 
 namespace cloud_print {
 
 // Sets Google Update registry keys after install or update.
 void SetGoogleUpdateKeys(const string16& product_id,
                          const string16& product_name);
 
 // Sets custom error message to show by Google Update installer
 void SetGoogleUpdateError(const string16& product_id, const string16& message);
 
@@ skipping 14 matching lines @@
 // Returns install location retrieved from control panel uninstall key.
 void DeleteProgramDir(const std::string& delete_switch);
 
 // Returns true if path is part of program files.
 bool IsProgramsFilesParent(const base::FilePath& path);
 
 }  // namespace cloud_print
 
 #endif  // CLOUD_PRINT_COMMON_INSTALL_UTILS_H_