base: Simplify the construction of MD5Digest.

base/md5.h

 // Copyright (c) 2011 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 BASE_MD5_H_
 #define BASE_MD5_H_
 
 #include <stdint.h>
 
 #include "base/base_export.h"
@@ skipping 18 matching lines @@
 //   MD5Update(&ctx, data1, length1);
 //   MD5Update(&ctx, data2, length2);
 //   ...
 //
 //   MD5Digest digest; // the result of the computation
 //   MD5Final(&digest, &ctx);
 //
 // You can call MD5DigestToBase16() to generate a string of the digest.
 
 // The output of an MD5 operation.
-struct MD5Digest {
-  uint8_t a[16];
-};
+typedef uint8_t MD5Digest[16];
 
 // Used for storing intermediate data during an MD5 computation. Callers
 // should not access the data.
 typedef char MD5Context[88];
 
 // Initializes the given MD5 context structure for subsequent calls to
 // MD5Update().
 BASE_EXPORT void MD5Init(MD5Context* context);
 
 // For the given buffer of |data| as a StringPiece, updates the given MD5
@@ skipping 16 matching lines @@
 // Computes the MD5 sum of the given data buffer with the given length.
 // The given 'digest' structure will be filled with the result data.
 BASE_EXPORT void MD5Sum(const void* data, size_t length, MD5Digest* digest);
 
 // Returns the MD5 (in hexadecimal) of a string.
 BASE_EXPORT std::string MD5String(const StringPiece& str);
 
 }  // namespace base
 
 #endif  // BASE_MD5_H_