Add an option to specify requested fields for fetching metadata.

storage/browser/fileapi/file_system_dir_url_request_job.cc

Index: storage/browser/fileapi/file_system_dir_url_request_job.cc
diff --git a/storage/browser/fileapi/file_system_dir_url_request_job.cc b/storage/browser/fileapi/file_system_dir_url_request_job.cc
index ac2118a292d383407433923f57652efe0e6279e9..fc91f3bc63f2034cc4b48ae3957441589c01f13a 100644
--- a/storage/browser/fileapi/file_system_dir_url_request_job.cc
+++ b/storage/browser/fileapi/file_system_dir_url_request_job.cc
@@ -162,7 +162,8 @@ void FileSystemDirURLRequestJob::GetMetadata(size_t index) {
       url_.path().Append(base::FilePath(entry.name)));
   DCHECK(url.is_valid());
   file_system_context_->operation_runner()->GetMetadata(
-      url,
+      url, FileSystemOperation::GET_METADATA_FIELD_SIZE |
+               FileSystemOperation::GET_METADATA_FIELD_LAST_MODIFIED,
       base::Bind(&FileSystemDirURLRequestJob::DidGetMetadata, this, index));
 }