storage: Cleanup class/struct forward declarations

storage/browser/fileapi/sandbox_file_stream_writer.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 STORAGE_BROWSER_FILEAPI_SANDBOX_FILE_STREAM_WRITER_H_
 #define STORAGE_BROWSER_FILEAPI_SANDBOX_FILE_STREAM_WRITER_H_
 
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "storage/browser/blob/shareable_file_reference.h"
 #include "storage/browser/fileapi/file_stream_writer.h"
 #include "storage/browser/fileapi/file_system_url.h"
 #include "storage/browser/fileapi/task_runner_bound_observer_list.h"
 #include "storage/browser/storage_browser_export.h"
 #include "storage/common/fileapi/file_system_types.h"
 #include "storage/common/quota/quota_types.h"
 #include "url/gurl.h"
 
 namespace storage {
 
 class FileSystemContext;
-class FileSystemQuotaUtil;
 class FileStreamWriter;
 
 class STORAGE_EXPORT SandboxFileStreamWriter
     : public NON_EXPORTED_BASE(FileStreamWriter) {
  public:
   SandboxFileStreamWriter(FileSystemContext* file_system_context,
                           const FileSystemURL& url,
                           int64_t initial_offset,
                           const UpdateObserverList& observers);
   ~SandboxFileStreamWriter() override;
@@ skipping 52 matching lines @@
   int64_t default_quota_;
 
   base::WeakPtrFactory<SandboxFileStreamWriter> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SandboxFileStreamWriter);
 };
 
 }  // namespace storage
 
 #endif  // STORAGE_BROWSER_FILEAPI_SANDBOX_FILE_STREAM_WRITER_H_