Replace ToLower calls to the new format

chrome/app/signature_validator_win.cc

 // 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.
 
 #include "chrome/app/signature_validator_win.h"
 
 #include <atlstr.h>
 #include <softpub.h>
 #include <windows.h>
 #include <wintrust.h>
@@ skipping 21 matching lines @@
   // Key blobs that are not an integral number of bytes are unsupported.
   if (crypt_blob.cUnusedBits != 0)
     return false;
 
   uint8 hash[crypto::kSHA256Length] = {};
 
   base::StringPiece key_bytes(reinterpret_cast<char*>(
       crypt_blob.pbData), crypt_blob.cbData);
   crypto::SHA256HashString(key_bytes, hash, crypto::kSHA256Length);
 
-  *public_key_hash =
-      base::StringToLowerASCII(base::HexEncode(hash, arraysize(hash)));
+  *public_key_hash = base::ToLowerASCII(base::HexEncode(hash, arraysize(hash)));
   return true;
 }
 
 // The traits class for HCERTSTORE handles that can be closed via
 // CertCloseStore() API.
 class CertStoreHandleTraits {
  public:
   typedef HCERTSTORE Handle;
 
   // Closes the handle.
@@ skipping 159 matching lines @@
   // to make sure the cert is current.
   std::vector<std::string>::const_iterator it = std::find(
       expected_hashes.begin(),
       expected_hashes.end(),
       cert_info.public_key_hash());
   if (it == expected_hashes.end() || !cert_info.IsValidNow())
     return false;
 
   return true;
 }