Add about flag for Data Saver rebranding

Bug: 928891
Change-Id: Icdcf8774a6d6d52444a79c765ba6b353b0fffd45
Reviewed-on: https://chromium-review.googlesource.com/c/1455315
Reviewed-by: Avi Drissman <[email protected]>
Reviewed-by: Tarun Bansal <[email protected]>
Commit-Queue: Robert Ogden <[email protected]>
Cr-Commit-Position: refs/heads/master@{#629727}
5 files changed