chrome: Cleanup class/struct forward declarations

chrome/browser/chromeos/file_system_provider/operations/read_file.h

 // Copyright 2014 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 CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_OPERATIONS_READ_FILE_H_
 #define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_OPERATIONS_READ_FILE_H_
 
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/files/file.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/chromeos/file_system_provider/operations/operation.h"
 #include "chrome/browser/chromeos/file_system_provider/provided_file_system_info.h"
 #include "chrome/browser/chromeos/file_system_provider/provided_file_system_interface.h"
 #include "chrome/browser/chromeos/file_system_provider/request_value.h"
 #include "net/base/io_buffer.h"
 #include "storage/browser/fileapi/async_file_util.h"
 
-namespace base {
-class FilePath;
-}  // namespace base
-
 namespace extensions {
 class EventRouter;
 }  // namespace extensions
 
 namespace chromeos {
 namespace file_system_provider {
 namespace operations {
 
 // Bridge between fileapi read file and providing extension's read fil request.
 // Created per request.
@@ skipping 27 matching lines @@
   const ProvidedFileSystemInterface::ReadChunkReceivedCallback callback_;
 
   DISALLOW_COPY_AND_ASSIGN(ReadFile);
 };
 
 }  // namespace operations
 }  // namespace file_system_provider
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_OPERATIONS_READ_FILE_H_