chrome: Cleanup class/struct forward declarations

chrome/browser/ui/webui/foreign_session_handler.h

 // Copyright 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_UI_WEBUI_FOREIGN_SESSION_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_FOREIGN_SESSION_HANDLER_H_
 
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/scoped_observer.h"
 #include "base/time/time.h"
 #include "chrome/browser/sessions/session_service.h"
 #include "components/sync/driver/sync_service_observer.h"
 #include "components/sync_sessions/open_tabs_ui_delegate.h"
 #include "content/public/browser/web_ui.h"
 #include "content/public/browser/web_ui_message_handler.h"
 
-namespace sessions {
-struct SessionTab;
-struct SessionWindow;
-}
-
 namespace syncer {
 class SyncService;
 }
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 namespace browser_sync {
 
@@ skipping 62 matching lines @@
   // The time at which this WebUI was created. Used to calculate how long
   // the WebUI was present before the sessions data was visible.
   base::TimeTicks load_attempt_time_;
 
   DISALLOW_COPY_AND_ASSIGN(ForeignSessionHandler);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_UI_WEBUI_FOREIGN_SESSION_HANDLER_H_