Here's a second starter bug, Lawrence. :)

We can discuss the details in person.

https://cs.chromium.org/chromium/src/chrome/browser/about_flags.cc?sq=package:chromium&dr=C&rcl=1473765485&l=2231

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/95059d1e7407f93bbaa9b8ce10ac0b4b7a5620f6

commit 95059d1e7407f93bbaa9b8ce10ac0b4b7a5620f6
Author: lawrencewu <lawrencewu@chromium.org>
Date: Mon Sep 19 18:07:02 2016

Log base::Features in Launch.FlagsAtStartup

This adds support for displaying overriding enabled base::Feature
features in the Launch.FlagsAtStartup histogram.

BUG= 642858 

Review-Url: https://codereview.chromium.org/2345033002
Cr-Commit-Position: refs/heads/master@{#419503}

[modify] https://crrev.com/95059d1e7407f93bbaa9b8ce10ac0b4b7a5620f6/chrome/browser/about_flags.cc
[modify] https://crrev.com/95059d1e7407f93bbaa9b8ce10ac0b4b7a5620f6/chrome/browser/about_flags.h
[modify] https://crrev.com/95059d1e7407f93bbaa9b8ce10ac0b4b7a5620f6/chrome/browser/about_flags_unittest.cc
[modify] https://crrev.com/95059d1e7407f93bbaa9b8ce10ac0b4b7a5620f6/chrome/browser/chromeos/login/session/user_session_manager.cc
[modify] https://crrev.com/95059d1e7407f93bbaa9b8ce10ac0b4b7a5620f6/components/flags_ui/flags_state.cc
[modify] https://crrev.com/95059d1e7407f93bbaa9b8ce10ac0b4b7a5620f6/components/flags_ui/flags_state.h
[modify] https://crrev.com/95059d1e7407f93bbaa9b8ce10ac0b4b7a5620f6/tools/metrics/histograms/histograms.xml

Woot! Marking as Fixed, but we'll need to wait a couple of days to verify the data via the dashboards.

Looks like the change is indeed working: https://uma.googleplex.com/p/chrome/histograms/?endDate=09-21-2016&dayCount=1&histograms=Launch.FlagsAtStartup&fixupData=true&showMax=true&filters=channel%2Ceq%2C1%2Cisofficial%2Ceq%2CTrue&implicitFilters=isofficial