This issue has been Available for over a year. If it's no longer important or seems unlikely to be fixed, please consider closing it out. If it is important, please re-triage the issue.

Sorry for the inconvenience if the bug really should have been left as Available.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/479cc17585a64910853e9949b053499ecbeca9a5

commit 479cc17585a64910853e9949b053499ecbeca9a5
Author: Peter Kasting <pkasting@chromium.org>
Date: Fri Sep 28 22:34:37 2018

Remove --enable-tab-audio-muting

Per UX leads, this is dead.

Bug:  752226 
Change-Id: Ie5a353ca973d75b06436a9fef3ac2534bd2b6a3d
Reviewed-on: https://chromium-review.googlesource.com/1241813
Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Reviewed-by: Sergey Volk <servolk@chromium.org>
Reviewed-by: Raymes Khoury <raymes@chromium.org>
Reviewed-by: Yuri Wiitala <miu@chromium.org>
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595237}
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/WATCHLISTS
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/about_flags.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/content_settings/sound_content_setting_observer.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/content_settings/sound_content_setting_observer_unittest.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/extensions/api/tabs/tabs_api.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/extensions/api/tabs/tabs_constants.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/extensions/api/tabs/tabs_constants.h
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/extensions/extension_tab_util.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/flag_descriptions.h
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/BUILD.gn
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/browser.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/tabs/tab_strip_model.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/tabs/tab_strip_model.h
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/tabs/tab_utils.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/tabs/tab_utils.h
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/views/frame/browser_view.cc
[add] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/views/tabs/alert_indicator.cc
[add] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/views/tabs/alert_indicator.h
[delete] https://crrev.com/338fc4950723e9e0006f0cd0551feb2c9c80f847/chrome/browser/ui/views/tabs/alert_indicator_button.cc
[delete] https://crrev.com/338fc4950723e9e0006f0cd0551feb2c9c80f847/chrome/browser/ui/views/tabs/alert_indicator_button.h
[delete] https://crrev.com/338fc4950723e9e0006f0cd0551feb2c9c80f847/chrome/browser/ui/views/tabs/alert_indicator_button_unittest.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/views/tabs/browser_tab_strip_controller.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/views/tabs/browser_tab_strip_controller.h
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/views/tabs/fake_base_tab_strip_controller.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/views/tabs/fake_base_tab_strip_controller.h
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/views/tabs/tab.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/views/tabs/tab.h
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/views/tabs/tab_controller.h
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/views/tabs/tab_strip.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/views/tabs/tab_strip.h
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/views/tabs/tab_strip_controller.h
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/browser/ui/views/tabs/tab_unittest.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/common/chrome_switches.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/common/chrome_switches.h
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chrome/test/BUILD.gn
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chromecast/browser/extensions/api/tabs/tabs_constants.cc
[modify] https://crrev.com/479cc17585a64910853e9949b053499ecbeca9a5/chromecast/browser/extensions/api/tabs/tabs_constants.h

Has a removal of a flag ever caused so many issues before?

The UX/UI lead needs to re-evaluate this stance based on real-world feedback. This feature was widely used in the community.

See comments here: https://developers.google.com/web/updates/2018/12/chrome-72-deps-rems
Here: https://www.reddit.com/r/chrome/comments/a7824e/removed_the_ability_to_mute_tabs/
Or just do a search and find all the people claiming about this across the internet.

In comment No. 78 for  issue 360372 , a chrome developer claimed that

> ´"Mute tab" in the context menu for tabs remains, and will continue to remain.`

It seems to have been removed as well. I cannot mute a tab from context menu, only whole websites. 

@7: Changing Chrome's built-in controls from being per-tab to per-site happened later as a distinct decision (which I was not party to).

talk about a completely stupid decision. "Hey lets remove this feature so many people use, for no good reason at all"

This is how you move people off chrome