net: Cleanup class/struct forward declarations

net/http/http_network_session_peer.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_HTTP_HTTP_NETWORK_SESSION_PEER_H_
 #define NET_HTTP_HTTP_NETWORK_SESSION_PEER_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "net/base/net_export.h"
 
 namespace net {
 
 class ClientSocketPoolManager;
 class HttpNetworkSession;
 class HttpStreamFactory;
 class NetworkThrottleManager;
-class ProxyService;
 
 class NET_EXPORT_PRIVATE HttpNetworkSessionPeer {
  public:
   // |session| should outlive the HttpNetworkSessionPeer.
   explicit HttpNetworkSessionPeer(HttpNetworkSession* session);
   ~HttpNetworkSessionPeer();
 
   void SetClientSocketPoolManager(
       std::unique_ptr<ClientSocketPoolManager> socket_pool_manager);
 
   void SetHttpStreamFactory(
       std::unique_ptr<HttpStreamFactory> http_stream_factory);
   void SetHttpStreamFactoryForWebSocket(
       std::unique_ptr<HttpStreamFactory> http_stream_factory_for_websocket);
 
   void SetNetworkStreamThrottler(
       std::unique_ptr<NetworkThrottleManager> network_throttle_manager);
 
  private:
   HttpNetworkSession* const session_;
 
   DISALLOW_COPY_AND_ASSIGN(HttpNetworkSessionPeer);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_NETWORK_SESSION_PEER_H_