components: Cleanup class/struct fwd declarations

components/sessions/core/base_session_service.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 COMPONENTS_SESSIONS_CORE_BASE_SESSION_SERVICE_H_
 #define COMPONENTS_SESSIONS_CORE_BASE_SESSION_SERVICE_H_
 
 #include <memory>
 
 #include "base/callback.h"
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
 #include "base/task/cancelable_task_tracker.h"
 #include "components/sessions/core/sessions_export.h"
 #include "url/gurl.h"
 
 
 namespace sessions {
 class BaseSessionServiceDelegate;
-class SerializedNavigationEntry;
 class SessionCommand;
 class SessionBackend;
 
 // BaseSessionService is the super class of both tab restore service and
 // session service. It contains commonality needed by both, in particular
 // it manages a set of SessionCommands that are periodically sent to a
 // SessionBackend.
 class SESSIONS_EXPORT BaseSessionService {
  public:
   // Identifies the type of session service this is. This is used by the
@@ skipping 96 matching lines @@
 
   // Used to invoke Save.
   base::WeakPtrFactory<BaseSessionService> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BaseSessionService);
 };
 
 }  // namespace sessions
 
 #endif  // COMPONENTS_SESSIONS_CORE_BASE_SESSION_SERVICE_H_