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

content/child/webcrypto/webcrypto_util.h

 // 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.
 
 #ifndef CONTENT_CHILD_WEBCRYPTO_WEBCRYPTO_UTIL_H_
 #define CONTENT_CHILD_WEBCRYPTO_WEBCRYPTO_UTIL_H_
 
 #include <stdint.h>
 #include <string>
 #include <vector>
 
 #include "base/strings/string_piece.h"
 #include "base/values.h"
 #include "content/common/content_export.h"
 #include "third_party/WebKit/public/platform/WebCryptoAlgorithm.h"
 #include "third_party/WebKit/public/platform/WebCryptoKey.h"
 
 namespace content {
 
 namespace webcrypto {
 
 class Status;
 
-// Returns a pointer to the start of |data|, or NULL if it is empty. This is a
-// convenience function for getting the pointer, and should not be used beyond
-// the expected lifetime of |data|.
-CONTENT_EXPORT const uint8_t* Uint8VectorStart(
-    const std::vector<uint8_t>& data);
-CONTENT_EXPORT uint8_t* Uint8VectorStart(std::vector<uint8_t>* data);
-
 // This function decodes unpadded 'base64url' encoded data, as described in
 // RFC4648 (http://www.ietf.org/rfc/rfc4648.txt) Section 5.
 // In Web Crypto, this type of encoding is only used inside JWK.
 CONTENT_EXPORT bool Base64DecodeUrlSafe(const std::string& input,
                                         std::string* output);
 
 // Returns an unpadded 'base64url' encoding of the input data, the opposite of
 // Base64DecodeUrlSafe() above.
 CONTENT_EXPORT std::string Base64EncodeUrlSafe(const base::StringPiece& input);
 CONTENT_EXPORT std::string Base64EncodeUrlSafe(
@@ skipping 51 matching lines @@
 Status VerifyAesKeyLengthForImport(unsigned int keylen_bytes);
 
 Status CheckKeyCreationUsages(blink::WebCryptoKeyUsageMask all_possible_usages,
                               blink::WebCryptoKeyUsageMask actual_usages);
 
 }  // namespace webcrypto
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_WEBCRYPTO_WEBCRYPTO_UTIL_H_