net: Cleanup class/struct forward declarations

net/url_request/url_request_throttler_entry.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.
 
 #ifndef NET_URL_REQUEST_URL_REQUEST_THROTTLER_ENTRY_H_
 #define NET_URL_REQUEST_URL_REQUEST_THROTTLER_ENTRY_H_
 
 #include <stdint.h>
 
 #include <queue>
 #include <string>
 
 #include "base/macros.h"
 #include "base/time/time.h"
 #include "net/base/backoff_entry.h"
 #include "net/base/net_export.h"
 #include "net/log/net_log_with_source.h"
 #include "net/url_request/url_request_throttler_entry_interface.h"
 
 namespace net {
 
-class NetworkDelegate;
 class URLRequestThrottlerManager;
 
 // URLRequestThrottlerEntry represents an entry of URLRequestThrottlerManager.
 // It analyzes requests of a specific URL over some period of time, in order to
 // deduce the back-off time for every request.
 // The back-off algorithm consists of two parts. Firstly, exponential back-off
 // is used when receiving 5XX server errors or malformed response bodies.
 // The exponential back-off rule is enforced by URLRequestHttpJob. Any
 // request sent during the back-off period will be cancelled.
 // Secondly, a sliding window is used to count recent requests to a given
@@ skipping 118 matching lines @@
   std::string url_id_;
 
   NetLogWithSource net_log_;
 
   DISALLOW_COPY_AND_ASSIGN(URLRequestThrottlerEntry);
 };
 
 }  // namespace net
 
 #endif  // NET_URL_REQUEST_URL_REQUEST_THROTTLER_ENTRY_H_