ppapi: Cleanup class/struct forward declarations

ppapi/proxy/tcp_socket_resource_base.h

 // Copyright 2013 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 PPAPI_PROXY_TCP_SOCKET_RESOURCE_BASE_H_
 #define PPAPI_PROXY_TCP_SOCKET_RESOURCE_BASE_H_
 
 #include <stdint.h>
 
 #include <queue>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "ppapi/c/ppb_tcp_socket.h"
 #include "ppapi/c/private/ppb_net_address_private.h"
 #include "ppapi/proxy/plugin_resource.h"
 #include "ppapi/proxy/ppapi_proxy_export.h"
 #include "ppapi/shared_impl/ppb_tcp_socket_shared.h"
 #include "ppapi/shared_impl/tracked_callback.h"
 
 namespace ppapi {
 
 class PPB_X509Certificate_Fields;
 class PPB_X509Certificate_Private_Shared;
-class SocketOptionData;
 
 namespace proxy {
 
 class PPAPI_PROXY_EXPORT TCPSocketResourceBase : public PluginResource {
  public:
   // TODO(yzshen): Move these constants to ppb_tcp_socket_shared.
   // The maximum number of bytes that each PpapiHostMsg_PPBTCPSocket_Read
   // message is allowed to request.
   static const int32_t kMaxReadSize;
   // The maximum number of bytes that each PpapiHostMsg_PPBTCPSocket_Write
@@ skipping 111 matching lines @@
 
   TCPSocketVersion version_;
 
   DISALLOW_COPY_AND_ASSIGN(TCPSocketResourceBase);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_TCP_SOCKET_RESOURCE_BASE_H_