Use a direct include of strings headers in cloud_print/.

cloud_print/service/win/local_security_policy.h

 // 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.
 
 #ifndef CLOUD_PRINT_SERVICE_WIN_LOCAL_SECURITY_POLICY_H_
 #define CLOUD_PRINT_SERVICE_WIN_LOCAL_SECURITY_POLICY_H_
 
 #include <wtypes.h>  // Has to be before ntsecapi.h
 #include <ntsecapi.h>
 
 #include "base/basictypes.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 
 extern const wchar_t kSeServiceLogonRight[];
 
 class LocalSecurityPolicy {
  public:
   LocalSecurityPolicy();
   ~LocalSecurityPolicy();
 
   bool Open();
   void Close();
 
   bool IsPrivilegeSet(const string16& username,
                       const string16& privilage) const;
   bool SetPrivilege(const string16& username, const string16& privilage);
 
  private:
   LSA_HANDLE policy_;
 
   DISALLOW_COPY_AND_ASSIGN(LocalSecurityPolicy);
 };
 
 #endif  // CLOUD_PRINT_SERVICE_WIN_LOCAL_SECURITY_POLICY_H_