Toggle active tab's audio mute with ctrl + m

[simonhong]

fix brave/brave-browser#26994

Resolves

Submitter Checklist:

• I confirm that no security/privacy review is needed, or that I have requested one
• There is a ticket for my issue
• Used Github auto-closing keywords in the PR description above
• Wrote a good PR/commit description
• Squashed any review feedback or "fixup" commits before merge, so that history is a record of what happened in the repo, not your PR
• Added appropriate labels (QA/Yes or QA/No; release-notes/include or release-notes/exclude; OS/...) to the associated issue
• Checked the PR locally: npm run test -- brave_browser_tests, npm run test -- brave_unit_tests, npm run lint, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
• Major classes, functions and non-trivial code blocks are well-commented
• Changes in component dependencies are properly reflected in gn
• Code follows the style guide
• Test plan is specified in PR before merging

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on
• All relevant documentation has been updated, for instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Custom-Headers
  • https://github.com/brave/brave-browser/wiki/Web-Compatibility-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

Test Plan:

1. Load youtube.com and play any clip
2. Check ctrl + m toggles audio mute

[fallaciousreasoning]

LGTM!

[github-actions]

⚠️ PR head is an unsigned commit
commit: e915dc9
reason: unsigned
Please follow the handbook to configure commit signing
cc: @simonhong

[GregJArnold]

Awesome! Thanks @simonhong.

[GregJArnold]

My only thought is that being able to mute a tab even if it's not actively playing sound would be nice - the other browsers work this way, and I'm sure people will get tripped up if they hit CTRL+M when there's no audio playing and it doesn't mute.

[simonhong]

Hmm, we can't assume that only one tab is playing audio. It would be rare but user could do that.
We are thinking to add another shortcut to mute all from active browser window. Maybe that's what you want?
cc @rebron

[GregJArnold]

I would think that it would toggle mute on the currently-active tab, whether or not it, or any other tab, is currently playing any sound.

[simonhong]

I'm tempting to change current ctrl + m to toggle all audible tabs(but maybe mostly only one) instead of toggling active tab only.
Although user could have multiple audible tabs but it's rare and that user would not use this ctrl + m if it toggles all that tabs.
I think it's more usable when ctrl + m toggles any tab as @GregJArnold suggested.
@rebron WDYT?