ppapi: Cleanup class/struct forward declarations

ppapi/proxy/url_loader_resource.h

 // Copyright (c) 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_URL_LOADER_RESOURCE_H_
 #define PPAPI_PROXY_URL_LOADER_RESOURCE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <deque>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "ppapi/c/trusted/ppb_url_loader_trusted.h"
 #include "ppapi/proxy/plugin_resource.h"
 #include "ppapi/proxy/ppapi_proxy_export.h"
 #include "ppapi/shared_impl/url_request_info_data.h"
 #include "ppapi/thunk/ppb_url_loader_api.h"
 
 namespace ppapi {
+
+struct URLResponseInfoData;
+
 namespace proxy {
 
 class URLResponseInfoResource;
 
 class PPAPI_PROXY_EXPORT URLLoaderResource
     : public PluginResource,
       public NON_EXPORTED_BASE(thunk::PPB_URLLoader_API) {
  public:
   // Constructor for plugin-initiated loads.
   URLLoaderResource(Connection connection,
@@ skipping 107 matching lines @@
   // The response info if we've received it.
   scoped_refptr<URLResponseInfoResource> response_info_;
 
   DISALLOW_COPY_AND_ASSIGN(URLLoaderResource);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_URL_LOADER_RESOURCE_H_