net: Cleanup class/struct forward declarations

net/base/test_proxy_delegate.h

 // Copyright 2016 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_BASE_TEST_PROXY_DELEGATE_H_
 #define NET_BASE_TEST_PROXY_DELEGATE_H_
 
 #include <string>
 
 #include "net/base/host_port_pair.h"
 #include "net/base/proxy_delegate.h"
 #include "net/proxy/proxy_server.h"
 
 class GURL;
 
 namespace net {
 
 class HttpRequestHeaders;
 class HttpResponseHeaders;
 class ProxyInfo;
 class ProxyService;
-class URLRequest;
 
 class TestProxyDelegate : public ProxyDelegate {
  public:
   TestProxyDelegate();
   ~TestProxyDelegate() override;
 
   bool on_before_tunnel_request_called() const {
     return on_before_tunnel_request_called_;
   }
 
@@ skipping 64 matching lines @@
   std::string on_tunnel_headers_received_status_line_;
   ProxyServer alternative_proxy_server_;
 
   // Number of times GetAlternativeProxy() method has been called.
   mutable int get_alternative_proxy_invocations_;
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_TEST_PROXY_DELEGATE_H_