Update from https://crrev.com/316786

net/http/http_cache_transaction.h

 // 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.
 
 // This file declares HttpCache::Transaction, a private class of HttpCache so
 // it should only be included by http_cache.cc
 
 #ifndef NET_HTTP_HTTP_CACHE_TRANSACTION_H_
 #define NET_HTTP_HTTP_CACHE_TRANSACTION_H_
 
@@ skipping 317 matching lines @@
   bool ConditionalizeRequest();
 
   // Makes sure that a 206 response is expected.  Returns true on success.
   // On success, handling_206_ will be set to true if we are processing a
   // partial entry.
   bool ValidatePartialResponse();
 
   // Handles a response validation error by bypassing the cache.
   void IgnoreRangeRequest();
 
-  // Removes content-length and byte range related info if needed.
+  // Fixes the response headers to match expectations for a HEAD request.
   void FixHeadersForHead();
 
   // Launches an asynchronous revalidation based on this transaction.
   void TriggerAsyncValidation();
 
   // Changes the response code of a range request to be 416 (Requested range not
   // satisfiable).
   void FailRangeRequest();
 
   // Setups the transaction for reading from the cache entry.
@@ skipping 132 matching lines @@
   BeforeProxyHeadersSentCallback before_proxy_headers_sent_callback_;
 
   base::WeakPtrFactory<Transaction> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Transaction);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_CACHE_TRANSACTION_H_