Add last_validated timestamp to GCM registration info.

Bug: 799483
Change-Id: Id180ebd58acefa8f047858101c586b940b435e70
Reviewed-on: https://chromium-review.googlesource.com/887083
Commit-Queue: Mugdha Lakhani <[email protected]>
Reviewed-by: Peter Beverloo <[email protected]>
Cr-Commit-Position: refs/heads/master@{#533268}
5 files changed