components: Cleanup class/struct fwd declarations

components/user_prefs/tracked/pref_hash_filter.h

 // Copyright 2013 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_USER_PREFS_TRACKED_PREF_HASH_FILTER_H_
 #define COMPONENTS_USER_PREFS_TRACKED_PREF_HASH_FILTER_H_
 
 #include <stddef.h>
 
 #include <map>
 #include <memory>
 #include <set>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/containers/scoped_ptr_hash_map.h"
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/optional.h"
 #include "components/user_prefs/tracked/hash_store_contents.h"
 #include "components/user_prefs/tracked/interceptable_pref_filter.h"
 #include "components/user_prefs/tracked/tracked_preference.h"
 
 class PrefHashStore;
 class PrefService;
-class PrefStore;
 class TrackedPreferenceValidationDelegate;
 
 namespace base {
 class DictionaryValue;
 class Time;
-class Value;
 }  // namespace base
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }  // namespace user_prefs
 
 // Intercepts preference values as they are loaded from disk and verifies them
 // using a PrefHashStore. Keeps the PrefHashStore contents up to date as values
 // are changed.
 class PrefHashFilter : public InterceptablePrefFilter {
@@ skipping 126 matching lines @@
   // FilterSerializeData.
   ChangedPathsMap changed_paths_;
 
   // Whether to report the validity of the super MAC at load time (via UMA).
   bool report_super_mac_validity_;
 
   DISALLOW_COPY_AND_ASSIGN(PrefHashFilter);
 };
 
 #endif  // COMPONENTS_PREFS_TRACKED_PREF_HASH_FILTER_H_