The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1db4a0bab64a90b7b6f2999f571b725fa813ea35

commit 1db4a0bab64a90b7b6f2999f571b725fa813ea35
Author: isherman <isherman@chromium.org>
Date: Sat May 20 08:02:02 2017

Make histogram_suffixes separators and enum labels required.

It's somewhat common for metric authors to specify the wrong separator when
using a histogram_suffixes element, as the default is underscore, whereas dot is
common. This CL makes it harder to use the wrong separator by making the
attribute required.

Relatedly, this CL makes enum labels required (fixing one enum that lacked
labels), and makes name attributes always required.

BUG= 724311 
TEST=git cl format
R=asvitkine@chromium.org

Review-Url: https://codereview.chromium.org/2894833005
Cr-Commit-Position: refs/heads/master@{#473425}

[modify] https://crrev.com/1db4a0bab64a90b7b6f2999f571b725fa813ea35/tools/metrics/actions/print_style.py
[modify] https://crrev.com/1db4a0bab64a90b7b6f2999f571b725fa813ea35/tools/metrics/common/pretty_print_xml.py
[modify] https://crrev.com/1db4a0bab64a90b7b6f2999f571b725fa813ea35/tools/metrics/histograms/enums.xml
[modify] https://crrev.com/1db4a0bab64a90b7b6f2999f571b725fa813ea35/tools/metrics/histograms/histograms.xml
[modify] https://crrev.com/1db4a0bab64a90b7b6f2999f571b725fa813ea35/tools/metrics/histograms/print_style.py

Fixed?