components: Cleanup class/struct fwd declarations

components/sync/syncable/mutable_entry.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_SYNC_SYNCABLE_MUTABLE_ENTRY_H_
 #define COMPONENTS_SYNC_SYNCABLE_MUTABLE_ENTRY_H_
 
 #include <stdint.h>
 
 #include <string>
 
 #include "base/macros.h"
 #include "components/sync/base/model_type.h"
 #include "components/sync/syncable/entry.h"
 #include "components/sync/syncable/metahandle_set.h"
 #include "components/sync/syncable/model_neutral_mutable_entry.h"
 
 namespace syncer {
 
-class WriteNode;
-
 namespace syncable {
 
 enum Create { CREATE };
 
 class WriteTransaction;
 
 // A mutable meta entry.  Changes get committed to the database when the
 // WriteTransaction is destroyed.
 class MutableEntry : public ModelNeutralMutableEntry {
   void Init(WriteTransaction* trans,
@@ skipping 55 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(MutableEntry);
 };
 
 // This function sets only the flags needed to get this entry to sync.
 bool MarkForSyncing(syncable::MutableEntry* e);
 
 }  // namespace syncable
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_SYNCABLE_MUTABLE_ENTRY_H_