The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8ae26c546edacc0ca7d3ebcd3642c94fc647158f

commit 8ae26c546edacc0ca7d3ebcd3642c94fc647158f
Author: Parastoo Geranmayeh <parastoog@google.com>
Date: Tue Jul 10 23:26:27 2018

[Autofill] Adding UKM for rationalization.

UKM is logged for the fields whose types are rationalized
because they shared the same server type predictions.
For now it includes two field types: Address
lines, and state/country.
Tests Added.
New UKM collection review: go/1121206-ukm-review.

Bug:  857601 ,  850552 
Change-Id: Ibcddf4ea3fb0a72cd59df7d1434b97c5e7c32f44
Reviewed-on: https://chromium-review.googlesource.com/1121206
Reviewed-by: Sebastien Seguin-Gagnon <sebsg@chromium.org>
Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Commit-Queue: Parastoo Geranmayeh <parastoog@google.com>
Cr-Commit-Position: refs/heads/master@{#573981}
[modify] https://crrev.com/8ae26c546edacc0ca7d3ebcd3642c94fc647158f/components/autofill/core/browser/autofill_manager.cc
[modify] https://crrev.com/8ae26c546edacc0ca7d3ebcd3642c94fc647158f/components/autofill/core/browser/autofill_manager.h
[modify] https://crrev.com/8ae26c546edacc0ca7d3ebcd3642c94fc647158f/components/autofill/core/browser/autofill_metrics.cc
[modify] https://crrev.com/8ae26c546edacc0ca7d3ebcd3642c94fc647158f/components/autofill/core/browser/autofill_metrics.h
[modify] https://crrev.com/8ae26c546edacc0ca7d3ebcd3642c94fc647158f/components/autofill/core/browser/autofill_metrics_unittest.cc
[modify] https://crrev.com/8ae26c546edacc0ca7d3ebcd3642c94fc647158f/components/autofill/core/browser/form_structure.cc
[modify] https://crrev.com/8ae26c546edacc0ca7d3ebcd3642c94fc647158f/components/autofill/core/browser/form_structure.h
[modify] https://crrev.com/8ae26c546edacc0ca7d3ebcd3642c94fc647158f/components/autofill/core/browser/form_structure_unittest.cc
[modify] https://crrev.com/8ae26c546edacc0ca7d3ebcd3642c94fc647158f/components/password_manager/core/browser/password_generation_manager_unittest.cc
[modify] https://crrev.com/8ae26c546edacc0ca7d3ebcd3642c94fc647158f/components/password_manager/core/browser/password_manager_unittest.cc
[modify] https://crrev.com/8ae26c546edacc0ca7d3ebcd3642c94fc647158f/tools/metrics/ukm/ukm.xml