net: Update the include paths of base/string_piece.h to its new location.

net/cert/x509_certificate_mac.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 "net/cert/x509_certificate.h"
 
 #include <CommonCrypto/CommonDigest.h>
 #include <CoreServices/CoreServices.h>
 #include <Security/Security.h>
 #include <time.h>
 
 #include <vector>
 
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/mac/mac_logging.h"
 #include "base/mac/scoped_cftyperef.h"
 #include "base/memory/singleton.h"
 #include "base/pickle.h"
 #include "base/sha1.h"
-#include "base/string_piece.h"
+#include "base/strings/string_piece.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/synchronization/lock.h"
 #include "crypto/cssm_init.h"
 #include "crypto/mac_security_services_lock.h"
 #include "crypto/nss_util.h"
 #include "crypto/rsa_private_key.h"
 #include "net/cert/x509_util_mac.h"
 #include "third_party/nss/mozilla/security/nss/lib/certdb/cert.h"
 
 using base::mac::ScopedCFTypeRef;
@@ skipping 793 matching lines @@
       *type = kPublicKeyTypeDH;
       break;
     default:
       *type = kPublicKeyTypeUnknown;
       *size_bits = 0;
       break;
   }
 }
 
 }  // namespace net