Add an option to specify requested fields for fetching metadata.

storage/browser/fileapi/file_system_operation_impl.h

 // Copyright 2013 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_IMPL_H_
 #define STORAGE_BROWSER_FILEAPI_FILE_SYSTEM_OPERATION_IMPL_H_
 
 #include <vector>
 
 #include "base/memory/ref_counted.h"
@@ skipping 35 matching lines @@
             const StatusCallback& callback) override;
   void Move(const FileSystemURL& src_url,
             const FileSystemURL& dest_url,
             CopyOrMoveOption option,
             const StatusCallback& callback) override;
   void DirectoryExists(const FileSystemURL& url,
                        const StatusCallback& callback) override;
   void FileExists(const FileSystemURL& url,
                   const StatusCallback& callback) override;
   void GetMetadata(const FileSystemURL& url,
+                   int fields,
                    const GetMetadataCallback& callback) override;
   void ReadDirectory(const FileSystemURL& url,
                      const ReadDirectoryCallback& callback) override;
   void Remove(const FileSystemURL& url,
               bool recursive,
               const StatusCallback& callback) override;
   void Write(const FileSystemURL& url,
              scoped_ptr<FileWriterDelegate> writer_delegate,
              scoped_ptr<net::URLRequest> blob_request,
              const WriteCallback& callback) override;
@@ skipping 129 matching lines @@
   OperationType pending_operation_;
 
   base::WeakPtrFactory<FileSystemOperationImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FileSystemOperationImpl);
 };
 
 }  // namespace storage
 
 #endif  // STORAGE_BROWSER_FILEAPI_FILE_SYSTEM_OPERATION_IMPL_H_