Use size_t as the type of key_length and digest_length arguments of HMAC.

crypto/hmac.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 "crypto/hmac.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "crypto/secure_util.h"
@@ skipping 29 matching lines @@
   return VerifyTruncated(data, digest);
 }
 
 bool HMAC::VerifyTruncated(const base::StringPiece& data,
                            const base::StringPiece& digest) const {
   if (digest.empty())
     return false;
   size_t digest_length = DigestLength();
   scoped_array<unsigned char> computed_digest(
       new unsigned char[digest_length]);
-  if (!Sign(data, computed_digest.get(), static_cast<int>(digest_length)))
+  if (!Sign(data, computed_digest.get(), digest_length))
     return false;
 
   return SecureMemEqual(digest.data(), computed_digest.get(),
                         std::min(digest.size(), digest_length));
 }
 
 }  // namespace crypto