Add TempFileManager and tests

Bug: chromium:757625
Change-Id: I0f68e43c7f9700d3d02d640d36c2d9a4523b4495
Reviewed-on: https://chromium-review.googlesource.com/894167
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Commit-Queue: Allen Vicencio <allenvic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534811}
4 files changed