Http cache: Remove a histogram.

net/http/http_cache_transaction.h

 // Copyright (c) 2010 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_
 #pragma once
@@ skipping 294 matching lines @@
   void DoomPartialEntry(bool delete_object);
 
   // Performs the needed work after receiving data from the network, when
   // working with range requests.
   int DoPartialNetworkReadCompleted(int result);
 
   // Performs the needed work after receiving data from the cache, when
   // working with range requests.
   int DoPartialCacheReadCompleted(int result);
 
-  // Sends a histogram with info about the response headers.
-  void HistogramHeaders(const HttpResponseHeaders* headers);
-
   // Called to signal completion of asynchronous IO.
   void OnIOComplete(int result);
 
   State next_state_;
   const HttpRequestInfo* request_;
   BoundNetLog net_log_;
   scoped_ptr<HttpRequestInfo> custom_request_;
   // If extra_headers specified a "if-modified-since" or "if-none-match",
   // |external_validation_| contains the value of those headers.
   ValidationHeaders external_validation_;
@@ skipping 24 matching lines @@
   uint64 final_upload_progress_;
   CompletionCallbackImpl<Transaction> io_callback_;
   scoped_refptr<CancelableCompletionCallback<Transaction> > cache_callback_;
   scoped_refptr<CancelableCompletionCallback<Transaction> >
       write_headers_callback_;
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_CACHE_TRANSACTION_H_