Add a pref to track password deletion reasons

A new pref is added to track the different operations that result in
password deletion. If no expected operation caused password deletion,
it's a case of password loss which needs to be investigated.

The pref is checked if a password loss occurred and then logged to a
histogram. For now there is only a 0 basket for unknown removal reason.
The other removal reasons will be added as follow-ups.
The pref is reset daily on Chrome startup.

Bug: 342519805
Change-Id: I98f920d79f4bfeb2ed7a66ff14a3820dba3aa8a7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5604443


Commit-Queue: Ivana Žužić <izuzic@google.com>
Reviewed-by: Mohamed Amir Yosef <mamir@chromium.org>
Reviewed-by: Dominic Battré <battre@chromium.org>
Reviewed-by: Viktor Semeniuk <vsemeniuk@google.com>
Cr-Commit-Position: refs/heads/main@{#1312833}