ppapi: Cleanup class/struct forward declarations

ppapi/thunk/ppb_url_loader_api.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_THUNK_URL_LOADER_API_H_
 #define PPAPI_THUNK_URL_LOADER_API_H_
 
 #include <stdint.h>
 
 #include "base/memory/ref_counted.h"
 #include "ppapi/c/ppb_url_loader.h"
 #include "ppapi/c/trusted/ppb_url_loader_trusted.h"
 
 namespace ppapi {
 
 class TrackedCallback;
 struct URLRequestInfoData;
-struct URLResponseInfoData;
 
 namespace thunk {
 
 class PPB_URLLoader_API {
  public:
   virtual ~PPB_URLLoader_API() {}
 
   // Open given the resource ID of a PPB_URLRequestInfo resource.
   virtual int32_t Open(PP_Resource request_id,
                        scoped_refptr<TrackedCallback> callback) = 0;
@@ skipping 21 matching lines @@
   // Trusted API.
   virtual void GrantUniversalAccess() = 0;
   virtual void RegisterStatusCallback(
       PP_URLLoaderTrusted_StatusCallback cb) = 0;
 };
 
 }  // namespace thunk
 }  // namespace ppapi
 
 #endif  // PPAPI_THUNK_URL_LOADER_API_H_