storage: Cleanup class/struct forward declarations

storage/browser/fileapi/file_system_operation.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_FILE_SYSTEM_OPERATION_H_
 #define STORAGE_BROWSER_FILEAPI_FILE_SYSTEM_OPERATION_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 12 matching lines @@
 }
 
 namespace net {
 class URLRequest;
 }
 
 namespace storage {
 class ShareableFileReference;
 }
 
-class GURL;
-
 namespace storage {
 
 class FileSystemContext;
 class FileSystemURL;
 class FileWriterDelegate;
 
 // The interface class for FileSystemOperation implementations.
 //
 // This interface defines file system operations required to implement
 // "File API: Directories and System"
@@ skipping 455 matching lines @@
     kOperationOpenFile,
     kOperationCloseFile,
     kOperationGetLocalPath,
     kOperationCancel,
   };
 };
 
 }  // namespace storage
 
 #endif  // STORAGE_BROWSER_FILEAPI_FILE_SYSTEM_OPERATION_H_