Implement a URLDataSource to load videos from disk for OOBE

This patch implements a URLDataSource that loads oobe video assets from
disk based on the provided chrome URL. It also installs the same for
the oobe web ui.

Bug: 878594
Change-Id: I443144d4e5ab65d313c0e56d8b988a9cb05e6109
Component: Video source, oobe
Reviewed-on: https://chromium-review.googlesource.com/1196145
Reviewed-by: Michael Giuffrida <[email protected]>
Commit-Queue: Malay Keshav <[email protected]>
Cr-Commit-Position: refs/heads/master@{#587889}
4 files changed