chrome: Cleanup class/struct forward declarations

chrome/browser/browsing_data/browsing_data_remover.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 CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_REMOVER_H_
 #define CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_REMOVER_H_
 
 #include <stdint.h>
 
 #include <queue>
@@ skipping 27 matching lines @@
 #include "chrome/browser/pepper_flash_settings_manager.h"
 #endif
 
 #if defined(OS_CHROMEOS)
 #include "chromeos/dbus/dbus_method_call_status.h"
 #endif
 
 class BrowsingDataFilterBuilder;
 class BrowsingDataFlashLSOHelper;
 class BrowsingDataRemoverFactory;
-class HostContentSettingsMap;
-class IOThread;
 class Profile;
 class WebappRegistry;
 
 namespace chrome_browser_net {
 class Predictor;
 }
 
 namespace content {
 class BrowserContext;
 class PluginDataRemover;
 class StoragePartition;
 }
 
-namespace net {
-class URLRequestContextGetter;
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // BrowsingDataRemover is responsible for removing data related to browsing:
 // visits in url database, downloads, cookies ...
 //
 //  USAGE:
 //
 //  0. Instantiation.
 //
 //       BrowsingDataRemover remover =
 //           BrowsingDataRemoverFactory::GetForBrowserContext(profile);
@@ skipping 495 matching lines @@
   // not initialised, so the registry must be mocked out.
   std::unique_ptr<WebappRegistry> webapp_registry_;
 #endif
 
   base::WeakPtrFactory<BrowsingDataRemover> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowsingDataRemover);
 };
 
 #endif  // CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_REMOVER_H_