components: Cleanup class/struct fwd declarations

components/filesystem/public/cpp/prefs/filesystem_json_pref_store.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_FILESYSTEM_PUBLIC_CPP_PREFS_FILESYSTEM_JSON_PREF_STORE_H_
 #define COMPONENTS_FILESYSTEM_PUBLIC_CPP_PREFS_FILESYSTEM_JSON_PREF_STORE_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 13 matching lines @@
 #include "components/filesystem/public/interfaces/file_system.mojom.h"
 #include "components/filesystem/public/interfaces/types.mojom.h"
 #include "components/prefs/base_prefs_export.h"
 #include "components/prefs/persistent_pref_store.h"
 #include "components/prefs/pref_filter.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 class PrefFilter;
 
 namespace base {
-class Clock;
 class DictionaryValue;
-class FilePath;
 class JsonPrefStoreLossyWriteTest;
 class Value;
 }
 
 namespace filesystem {
 
 // A forked, hack'n'slashed copy of base::JsonPrefStore which writes its
 // preference data to the mojo filesystem instead of the real
 // filesystem. Unlike base::JsonPrefStore, this class can safely be used inside
 // a sandboxed process.
@@ skipping 124 matching lines @@
   bool filtering_in_progress_;
   bool pending_lossy_write_;
   PrefReadError read_error_;
 
   DISALLOW_COPY_AND_ASSIGN(FilesystemJsonPrefStore);
 };
 
 }  // namespace filesystem
 
 #endif  // COMPONENTS_FILESYSTEM_PUBLIC_CPP_PREFS_FILESYSTEM_JSON_PREF_STORE_H_