content: Cleanup class/struct forward declarations

content/renderer/p2p/host_address_request.h

 // Copyright (c) 2011 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 CONTENT_RENDERER_P2P_HOST_ADDRESS_REQUEST_H_
 #define CONTENT_RENDERER_P2P_HOST_ADDRESS_REQUEST_H_
 
 #include <stdint.h>
 
 #include <string>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 #include "net/base/ip_address.h"
 #include "third_party/webrtc/base/asyncresolverinterface.h"
 
 namespace base {
-class MessageLoop;
 class SingleThreadTaskRunner;
 }  // namespace base
 
 namespace content {
 
 class P2PSocketDispatcher;
 
 // P2PAsyncAddressResolver performs DNS hostname resolution. It's used
 // to resolve addresses of STUN and relay servers.
 class P2PAsyncAddressResolver
@@ skipping 39 matching lines @@
   bool registered_;
   std::vector<rtc::IPAddress> addresses_;
   DoneCallback done_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(P2PAsyncAddressResolver);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_P2P_HOST_ADDRESS_REQUEST_H_