components: Cleanup class/struct fwd declarations

components/sync_preferences/pref_model_associator.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 COMPONENTS_SYNC_PREFERENCES_PREF_MODEL_ASSOCIATOR_H_
 #define COMPONENTS_SYNC_PREFERENCES_PREF_MODEL_ASSOCIATOR_H_
 
 #include <map>
 #include <memory>
 #include <set>
@@ skipping 14 matching lines @@
 class Value;
 }
 
 namespace sync_pb {
 class PreferenceSpecifics;
 }
 
 namespace sync_preferences {
 
 class PrefModelAssociatorClient;
-class PrefRegistrySyncable;
 class PrefServiceSyncable;
 
 // Contains all preference sync related logic.
 // TODO(sync): Merge this into PrefService once we separate the profile
 // PrefService from the local state PrefService.
 class PrefModelAssociator : public syncer::SyncableService,
                             public base::NonThreadSafe {
  public:
   // Constructs a PrefModelAssociator initializing the |client_| and |type_|
   // instance variable. The |client| is not owned by this object and the caller
@@ skipping 153 matching lines @@
   const PrefModelAssociatorClient* client_;  // Weak.
 
   std::vector<base::Closure> callback_list_;
 
   DISALLOW_COPY_AND_ASSIGN(PrefModelAssociator);
 };
 
 }  // namespace sync_preferences
 
 #endif  // COMPONENTS_SYNC_PREFERENCES_PREF_MODEL_ASSOCIATOR_H_