components: Cleanup class/struct fwd declarations

components/reading_list/reading_list_model.h

 // Copyright 2016 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_READING_LIST_READING_LIST_MODEL_H_
 #define COMPONENTS_READING_LIST_READING_LIST_MODEL_H_
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/observer_list.h"
 #include "base/threading/non_thread_safe.h"
 #include "components/reading_list/reading_list_entry.h"
 #include "components/reading_list/reading_list_model_observer.h"
 
 class GURL;
 class ReadingListEntry;
 class ReadingListModel;
-class ReadingListStore;
 class ScopedReadingListBatchUpdate;
 
-namespace ios {
-class ChromeBrowserState;
-}
-
 namespace syncer {
 class ModelTypeSyncBridge;
 }
 
 // The reading list model contains two list of entries: one of unread urls, the
 // other of read ones. This object should only be accessed from one thread
 // (Usually the main thread). The observers callbacks are also sent on the main
 // thread.
 class ReadingListModel : public base::NonThreadSafe {
  public:
@@ skipping 114 matching lines @@
   // Called when model is leaving batch update mode.
   virtual void LeavingBatchUpdates();
 
  private:
   unsigned int current_batch_updates_count_;
 
   DISALLOW_COPY_AND_ASSIGN(ReadingListModel);
 };
 
 #endif  // COMPONENTS_READING_LIST_READING_LIST_MODEL_H_