Remove the implicit add of Vary: Cookie on redirected requests

net/http/http_vary_data.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 "net/http/http_vary_data.h"
 
 #include <stdlib.h>
 
 #include "base/pickle.h"
 #include "base/strings/string_util.h"
@@ skipping 23 matching lines @@
   //
   size_t iter = 0;
   std::string name = "vary", request_header;
   while (response_headers.EnumerateHeader(&iter, name, &request_header)) {
     if (request_header == "*")
       return false;
     AddField(request_info, request_header, &ctx);
     processed_header = true;
   }
 
-  // Add an implicit 'Vary: cookie' header to any redirect to avoid redirect
-  // loops which may result from redirects that are incorrectly marked as
-  // cachable by the server.  Unfortunately, other browsers do not cache
-  // redirects that result from requests containing a cookie header.  We are
-  // treading on untested waters here, so we want to be extra careful to make
-  // sure we do not end up with a redirect loop served from cache.
-  //
-  // If there is an explicit 'Vary: cookie' header, then we will just end up
-  // digesting the cookie header twice.  Not a problem.
-  //
-  std::string location;
-  if (response_headers.IsRedirect(&location)) {
-    AddField(request_info, "cookie", &ctx);
-    processed_header = true;
-  }
-
   if (!processed_header)
     return false;
 
   base::MD5Final(&request_digest_, &ctx);
   return is_valid_ = true;
 }
 
 bool HttpVaryData::InitFromPickle(base::PickleIterator* iter) {
   is_valid_ = false;
   const char* data;
@@ skipping 47 matching lines @@
   // 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);
 }
 
 }  // namespace net