tree fad53ff8ed1e773eb8ae3f2c587db9e3ed41cb54
parent edfa1d48cb185f83b9274d07e5b359abd1ec62b4
author David Zeuthen <zeuthen@chromium.org> 1398456747 -0700
committer chrome-internal-fetch <chrome-internal-fetch@google.com> 1398891938 +0000

metrics: Emit kAbnormalTermination if last update attempt failed.

This allows us to track how many update attempts terminates
abnormally, for example if the device is rebooted in the middle of an
update or if update_engine crashes. We use a marker state variable
(aka a "prefs" file) to keep track of this.

Note that we don't currently report any of the other metrics in the
UpdateEngine.Attempt.* namespace. If necessary, this can be changed in
the future - I left a TODO item in the code with more details.

BUG=chromium:357676
TEST=New unit tests + Unit tests pass + Manual tests.

Change-Id: I83fe284c7c46917c0c55b92314c58098e2fd1789
Reviewed-on: https://chromium-review.googlesource.com/197175
Reviewed-by: Alex Deymo <deymo@chromium.org>
Tested-by: David Zeuthen <zeuthen@chromium.org>
Commit-Queue: David Zeuthen <zeuthen@chromium.org>