GitLab

Add new update progress calculation which is based on total time left
expectation. New update progress is gradually changed during the update.

Bug: 1117036
Change-Id: I11478e06af64137ebc7643495d198537d1031657
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2358681Reviewed-by: Roman Sorokin [CET] <rsorokin@chromium.org>
Commit-Queue: Roman Aleksandrov <raleksandrov@google.com>
Cr-Commit-Position: refs/heads/master@{#799621}