components: Cleanup class/struct fwd declarations

components/drive/chromeos/file_system/operation_delegate.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 COMPONENTS_DRIVE_CHROMEOS_FILE_SYSTEM_OPERATION_DELEGATE_H_
 #define COMPONENTS_DRIVE_CHROMEOS_FILE_SYSTEM_OPERATION_DELEGATE_H_
 
 #include "components/drive/file_errors.h"
 
-namespace base {
-class FilePath;
-}
-
 namespace drive {
 
 struct ClientContext;
 class FileChange;
 
 namespace file_system {
 
 // Error type of sync client.
 // Keep it synced with "DriveSyncErrorType" in file_manager_private.idl.
 enum DriveSyncErrorType {
@@ skipping 28 matching lines @@
   // Waits for the sync task to complete and runs the callback.
   // Returns false if no task is found for the spcecified ID.
   virtual bool WaitForSyncComplete(const std::string& local_id,
                                    const FileOperationCallback& callback);
 };
 
 }  // namespace file_system
 }  // namespace drive
 
 #endif  // COMPONENTS_DRIVE_CHROMEOS_FILE_SYSTEM_OPERATION_DELEGATE_H_