Use TimeTicks instead of Time for crostini notification times

We currently use base::Time to provide time left estimates in crostini
notifications. This is the wrong type for tracking how much time a task
takes as it is not guaranteed to be non-decreasing. This CL changes
these to the correct type of base::TimeTicks.

Change-Id: Ic4731e8636997a0fe605f08d0ccbd91a01e9df95
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1668887
Commit-Queue: Timothy Loh <timloh@chromium.org>
Commit-Queue: Joel Hockey <joelhockey@chromium.org>
Auto-Submit: Timothy Loh <timloh@chromium.org>
Reviewed-by: Joel Hockey <joelhockey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#670808}
5 files changed