[refactor] Replace custom utility function with base's "vector_as_array()"

content/child/webcrypto/openssl/hmac_openssl.cc

 // Copyright 2014 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 <openssl/hmac.h>
 
 #include "base/logging.h"
+#include "base/stl_util.h"
 #include "content/child/webcrypto/algorithm_implementation.h"
 #include "content/child/webcrypto/crypto_data.h"
 #include "content/child/webcrypto/jwk.h"
 #include "content/child/webcrypto/openssl/key_openssl.h"
 #include "content/child/webcrypto/openssl/sym_key_openssl.h"
 #include "content/child/webcrypto/openssl/util_openssl.h"
 #include "content/child/webcrypto/status.h"
 #include "content/child/webcrypto/webcrypto_util.h"
 #include "crypto/openssl_util.h"
 #include "crypto/secure_util.h"
@@ skipping 23 matching lines @@
   // OpenSSL wierdness here.
   // First, HMAC() needs a void* for the key data, so make one up front as a
   // cosmetic to avoid a cast. Second, OpenSSL does not like a NULL key,
   // which will result if the raw_key vector is empty; an entirely valid
   // case. Handle this specific case by pointing to an empty array.
   const unsigned char null_key[] = {};
   const void* const raw_key_voidp = raw_key.size() ? &raw_key[0] : null_key;
 
   buffer->resize(hmac_expected_length);
   crypto::ScopedOpenSSLSafeSizeBuffer<EVP_MAX_MD_SIZE> hmac_result(
-      Uint8VectorStart(buffer), hmac_expected_length);
+      vector_as_array(buffer), hmac_expected_length);
 
   unsigned int hmac_actual_length;
   unsigned char* const success = HMAC(digest_algorithm,
                                       raw_key_voidp,
                                       raw_key.size(),
                                       data.bytes(),
                                       data.byte_length(),
                                       hmac_result.safe_buffer(),
                                       &hmac_actual_length);
   if (!success || hmac_actual_length != hmac_expected_length)
@@ skipping 124 matching lines @@
                         const CryptoData& data,
                         bool* signature_match) const OVERRIDE {
     std::vector<uint8_t> result;
     Status status = Sign(algorithm, key, data, &result);
 
     if (status.IsError())
       return status;
 
     // Do not allow verification of truncated MACs.
     *signature_match = result.size() == signature.byte_length() &&
-                       crypto::SecureMemEqual(Uint8VectorStart(result),
+                       crypto::SecureMemEqual(vector_as_array(&result),
                                               signature.bytes(),
                                               signature.byte_length());
 
     return Status::Success();
   }
 };
 
 }  // namespace
 
 AlgorithmImplementation* CreatePlatformHmacImplementation() {
   return new HmacImplementation;
 }
 
 }  // namespace webcrypto
 
 }  // namespace content