MD5Update function uses StringPiece instead of raw buffer.

net/http/http_vary_data.cc

 // 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.
 
 #include "net/http/http_vary_data.h"
 
 #include <stdlib.h>
 
 #include "base/pickle.h"
 #include "base/string_util.h"
@@ skipping 102 matching lines @@
                             const std::string& request_header,
                             base::MD5Context* ctx) {
   std::string request_value = GetRequestValue(request_info, request_header);
 
   // Append a character that cannot appear in the request header line so that we
   // protect against case where the concatenation of two request headers could
   // look the same for a variety of values for the individual request headers.
   // For example, "foo: 12\nbar: 3" looks like "foo: 1\nbar: 23" otherwise.
   request_value.append(1, '\n');
 
-  base::MD5Update(ctx, request_value.data(), request_value.size());
+  base::MD5Update(ctx, request_value);
 }
 
 }  // namespace net