Http Cache: Update vary data after a 304.

net/http/http_cache_transaction.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_cache_transaction.h"
 
 #include "build/build_config.h"
 
 #if defined(OS_POSIX)
 #include <unistd.h>
@@ skipping 1647 matching lines @@
 
   next_state_ = STATE_UPDATE_CACHED_RESPONSE_COMPLETE;
   int rv = OK;
   // Update cached response based on headers in new_response.
   // TODO(wtc): should we update cached certificate (response_.ssl_info), too?
   response_.headers->Update(*new_response_->headers.get());
   response_.response_time = new_response_->response_time;
   response_.request_time = new_response_->request_time;
   response_.network_accessed = new_response_->network_accessed;
   response_.unused_since_prefetch = new_response_->unused_since_prefetch;
+  if (new_response_->vary_data.is_valid()) {
+    response_.vary_data = new_response_->vary_data;
+  } else if (response_.vary_data.is_valid()) {
+    // There is a vary header in the stored response but not in the current one.
+    // Update the data with the new request headers.
+    HttpVaryData new_vary_data;
+    new_vary_data.Init(*request_, *response_.headers.get());
+    response_.vary_data = new_vary_data;
+  }
 
   if (response_.headers->HasHeaderValue("cache-control", "no-store")) {
     if (!entry_->doomed) {
       int ret = cache_->DoomEntry(cache_key_, NULL);
       DCHECK_EQ(OK, ret);
     }
   } else {
     // If we are already reading, we already updated the headers for this
     // request; doing it again will change Content-Length.
     if (!reading_) {
@@ skipping 1592 matching lines @@
 
 void HttpCache::Transaction::OnIOComplete(int result) {
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/422516 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION("422516 Transaction::OnIOComplete"));
 
   DoLoop(result);
 }
 
 }  // namespace net