The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4607ff8dda82d923660048e2648cc29faf6d7a02

commit 4607ff8dda82d923660048e2648cc29faf6d7a02
Author: Tommy Steimel <steimel@chromium.org>
Date: Wed Nov 29 05:06:16 2017

Update logic for showing Mute Site checkmark on Window menu on Mac

Currently, the logic for toggling the checkmark only looks at whether
the tabs are currently muted. However, when the SoundContentSetting
feature is enabled, the actual functionality depends on the content
settings instead. This CL checks content settings when the
SoundContentSetting is enabled.

Bug:  788982 
Change-Id: I34a1e75f0480e6d902400f6b56d399a9b3065b9d
Reviewed-on: https://chromium-review.googlesource.com/792597
Commit-Queue: Tommy Steimel <steimel@chromium.org>
Reviewed-by: Trent Apted <tapted@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Cr-Commit-Position: refs/heads/master@{#520011}
[modify] https://crrev.com/4607ff8dda82d923660048e2648cc29faf6d7a02/chrome/browser/ui/cocoa/browser_window_command_handler.mm

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c447798a78fe2915de39ab9d9492ea23ba3f2de3

commit c447798a78fe2915de39ab9d9492ea23ba3f2de3
Author: Tommy Steimel <steimel@chromium.org>
Date: Wed Nov 29 18:07:18 2017

Change Mute Tab to Mute Site on the Window menu on Mac

Currently, the Window menu shows "Mute Tab", which used to match the
tab dropdown's "Mute tab". However, the tab dropdown text has been
changed to "Mute site" for site muting, so we want to change the Window
menu text to "Mute Site" to match.

This should in theory be behind the SoundContentSetting feature flag,
but that's not doable in a .xib file.

Bug:  788982 
Change-Id: If36c57b9fbc536d1eed95e13d23032c38da22499
Reviewed-on: https://chromium-review.googlesource.com/792299
Reviewed-by: Trent Apted <tapted@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: Jay Civelli <jcivelli@chromium.org>
Commit-Queue: Tommy Steimel <steimel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#520163}
[modify] https://crrev.com/c447798a78fe2915de39ab9d9492ea23ba3f2de3/chrome/app/chrome_command_ids.h
[modify] https://crrev.com/c447798a78fe2915de39ab9d9492ea23ba3f2de3/chrome/app/generated_resources.grd
[modify] https://crrev.com/c447798a78fe2915de39ab9d9492ea23ba3f2de3/chrome/app/nibs/MainMenu.xib
[modify] https://crrev.com/c447798a78fe2915de39ab9d9492ea23ba3f2de3/chrome/browser/ui/browser_command_controller.cc
[modify] https://crrev.com/c447798a78fe2915de39ab9d9492ea23ba3f2de3/chrome/browser/ui/browser_commands.cc
[modify] https://crrev.com/c447798a78fe2915de39ab9d9492ea23ba3f2de3/chrome/browser/ui/browser_commands.h
[modify] https://crrev.com/c447798a78fe2915de39ab9d9492ea23ba3f2de3/chrome/browser/ui/cocoa/browser_window_command_handler.mm

Verified this issue on Mac OS 10.12.6 using chrome latest M64 #64.0.3282.79 by following steps mentioned below.

1. Navigated to YouTube.com and played some random video
2. Right clicked on Tab menu
3. Observed "Mute Tab" is replaced with "Mute Site" as expected. 

Hence adding TE-Verified label for M64.