ppapi: Cleanup class/struct forward declarations

ppapi/proxy/plugin_resource.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 PPAPI_PROXY_PLUGIN_RESOURCE_H_
 #define PPAPI_PROXY_PLUGIN_RESOURCE_H_
 
 #include <stdint.h>
 
 #include <map>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "ipc/ipc_message.h"
 #include "ipc/ipc_sender.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/proxy/connection.h"
 #include "ppapi/proxy/plugin_resource_callback.h"
 #include "ppapi/proxy/ppapi_message_utils.h"
 #include "ppapi/proxy/ppapi_proxy_export.h"
 #include "ppapi/proxy/resource_message_params.h"
 #include "ppapi/proxy/resource_reply_thread_registrar.h"
 #include "ppapi/shared_impl/resource.h"
 #include "ppapi/shared_impl/tracked_callback.h"
 namespace ppapi {
 namespace proxy {
 
-class PluginDispatcher;
-
 class PPAPI_PROXY_EXPORT PluginResource : public Resource {
  public:
   enum Destination {
     RENDERER = 0,
     BROWSER = 1
   };
 
   PluginResource(Connection connection, PP_Instance instance);
   ~PluginResource() override;
 
@@ skipping 239 matching lines @@
 
   if (UnpackMessage<ReplyMsgClass>(reply, a, b, c, d, e))
     return result;
   return PP_ERROR_FAILED;
 }
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_PLUGIN_RESOURCE_H_