The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/04c8595b3d4c10d8ce02c057084a8e46df0d8c1e

commit 04c8595b3d4c10d8ce02c057084a8e46df0d8c1e
Author: Mounir Lamouri <mlamouri@chromium.org>
Date: Thu Dec 06 17:55:34 2018

Autoplay: remove cross-origin autoplay policy from //chrome and //content.

This isn't removing the code in Blink but prevents users from setting this
autoplay policy.

Bug: 911795
Change-Id: I8803813a1971d2c0082af164ed8d73a48e3a1cf7
Reviewed-on: https://chromium-review.googlesource.com/c/1362225
Reviewed-by: Becca Hughes <beccahughes@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Commit-Queue: Mounir Lamouri <mlamouri@chromium.org>
Cr-Commit-Position: refs/heads/master@{#614408}
[modify] https://crrev.com/04c8595b3d4c10d8ce02c057084a8e46df0d8c1e/chrome/browser/about_flags.cc
[modify] https://crrev.com/04c8595b3d4c10d8ce02c057084a8e46df0d8c1e/chrome/browser/ui/webui/media/media_engagement_ui.cc
[modify] https://crrev.com/04c8595b3d4c10d8ce02c057084a8e46df0d8c1e/content/browser/renderer_host/render_view_host_impl.cc
[modify] https://crrev.com/04c8595b3d4c10d8ce02c057084a8e46df0d8c1e/content/public/common/web_preferences.h
[modify] https://crrev.com/04c8595b3d4c10d8ce02c057084a8e46df0d8c1e/content/renderer/render_view_impl.cc
[modify] https://crrev.com/04c8595b3d4c10d8ce02c057084a8e46df0d8c1e/media/base/media_switches.cc
[modify] https://crrev.com/04c8595b3d4c10d8ce02c057084a8e46df0d8c1e/media/base/media_switches.h