Implement WriteFile in SmbFileSystem

Implements WriteFile in SmbFileSystem using TempFileManager.

Bug: chromium:757625
Change-Id: I176079aca1bb752f628c86942f2ee89b46c19729
Reviewed-on: https://chromium-review.googlesource.com/894983
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Commit-Queue: Allen Vicencio <allenvic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534834}
2 files changed