smb_client: Implement GetMetadata

Implement GetMetadata for SmbFileSystem.

Bug: chromium:757625
Change-Id: I02c4c7e7527047f4146765d1059c7a4409470f13
Reviewed-on: https://chromium-review.googlesource.com/826257
Commit-Queue: Allen Vicencio <allenvic@chromium.org>
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#525797}
2 files changed