The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/24fd9180eb9c1fe65387ba42ff2a34da79fce16a

commit 24fd9180eb9c1fe65387ba42ff2a34da79fce16a
Author: Tommy Steimel <steimel@chromium.org>
Date: Wed Nov 07 23:34:10 2018

[Global Media Controls] Add feature flag for hardware key handling

This CL adds a feature flag to toggle hardware key handling. This
is currently unused and disabled by default.

Bug:  902792 
Change-Id: Ic1dfd70a81f6aa7abb8fd79b504b0d3bd05843e3
Reviewed-on: https://chromium-review.googlesource.com/c/1323798
Reviewed-by: Becca Hughes <beccahughes@chromium.org>
Commit-Queue: Tommy Steimel <steimel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606207}
[modify] https://crrev.com/24fd9180eb9c1fe65387ba42ff2a34da79fce16a/media/base/media_switches.cc
[modify] https://crrev.com/24fd9180eb9c1fe65387ba42ff2a34da79fce16a/media/base/media_switches.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1aadd7b73a3edebe9ee35eff524c3c155b50a55b

commit 1aadd7b73a3edebe9ee35eff524c3c155b50a55b
Author: Tommy Steimel <steimel@chromium.org>
Date: Fri Jan 18 19:39:42 2019

[Global Media Controls] Add HardwareMediaKeyHandling to about flags

Bug:  902792 
Change-Id: I8341a1cfd4a4c0046e35d0dd37b1e0742d92fd51
Reviewed-on: https://chromium-review.googlesource.com/c/1418398
Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Becca Hughes <beccahughes@chromium.org>
Commit-Queue: Tommy Steimel <steimel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#624239}
[modify] https://crrev.com/1aadd7b73a3edebe9ee35eff524c3c155b50a55b/chrome/browser/about_flags.cc
[modify] https://crrev.com/1aadd7b73a3edebe9ee35eff524c3c155b50a55b/chrome/browser/flag-metadata.json
[modify] https://crrev.com/1aadd7b73a3edebe9ee35eff524c3c155b50a55b/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/1aadd7b73a3edebe9ee35eff524c3c155b50a55b/chrome/browser/flag_descriptions.h
[modify] https://crrev.com/1aadd7b73a3edebe9ee35eff524c3c155b50a55b/tools/metrics/histograms/enums.xml