content: Cleanup class/struct forward declarations

content/browser/download/download_resource_handler.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 CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_RESOURCE_HANDLER_H_
 #define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_RESOURCE_HANDLER_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "content/browser/download/download_request_core.h"
 #include "content/browser/loader/resource_handler.h"
 #include "content/public/browser/download_interrupt_reasons.h"
 #include "content/public/browser/download_manager.h"
 #include "content/public/browser/download_save_info.h"
 #include "content/public/browser/download_url_parameters.h"
 
 namespace net {
 class URLRequest;
 }  // namespace net
 
 namespace content {
 class ByteStreamReader;
-class ByteStreamWriter;
-class DownloadRequestHandle;
-class PowerSaveBlocker;
 struct DownloadCreateInfo;
 
 // Forwards data to the download thread.
 class CONTENT_EXPORT DownloadResourceHandler
     : public ResourceHandler,
       public DownloadRequestCore::Delegate,
       public base::SupportsWeakPtr<DownloadResourceHandler> {
  public:
   struct DownloadTabInfo;
 
@@ skipping 61 matching lines @@
   // deletion must occur on the IO thread.
   std::unique_ptr<DownloadTabInfo> tab_info_;
 
   DownloadRequestCore core_;
   DISALLOW_COPY_AND_ASSIGN(DownloadResourceHandler);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_RESOURCE_HANDLER_H_