The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7aaccf95fda3415c10feaa5947f6b353045d33e3

commit 7aaccf95fda3415c10feaa5947f6b353045d33e3
Author: Ian Vollick <vollick@chromium.org>
Date: Sat Apr 07 23:10:43 2018

[xr] Add a flag for enabling XR hit test support

Although there is no API yet, this flag will allow us to start working
on code that will support such an API in the future.

Bug:  830039 
Change-Id: I770b210c088f6c231116e5a7660d4b49a18cdc96
Reviewed-on: https://chromium-review.googlesource.com/1000316
Commit-Queue: Ian Vollick <vollick@chromium.org>
Reviewed-by: David Dorwin <ddorwin@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#549073}
[modify] https://crrev.com/7aaccf95fda3415c10feaa5947f6b353045d33e3/chrome/browser/about_flags.cc
[modify] https://crrev.com/7aaccf95fda3415c10feaa5947f6b353045d33e3/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/7aaccf95fda3415c10feaa5947f6b353045d33e3/chrome/browser/flag_descriptions.h
[modify] https://crrev.com/7aaccf95fda3415c10feaa5947f6b353045d33e3/content/public/common/content_features.cc
[modify] https://crrev.com/7aaccf95fda3415c10feaa5947f6b353045d33e3/content/public/common/content_features.h
[modify] https://crrev.com/7aaccf95fda3415c10feaa5947f6b353045d33e3/tools/metrics/histograms/enums.xml