The work on supporting Fission in DevTools started with enabling the Browser Toolbox to inspect/debug multiple processes.

This work is happening behind the pref devtools.browsertoolbox.fission (defined here).

Once this work is complete, we should enable the pref so the new "Omniscient" Browser Toolbox can be used by default everywhere.

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Tracking for Fission Nightly (M6)

Tracking for Fission Nightly (M6)

Trying to list the small tweaks we might want to do before enabling:

• remove emojis in the title
• localize settings checkbox
• add a learn more link next to the settings checkbox, instead of the warning WIP warning (need to have a page to link to however)
• maybe rename the "Main Process" target in about:debugging (but I don't have a good name)

Backed out for dt failures on browser_aboutdebugging_process_main.js

Backout link: https://hg.mozilla.org/integration/autoland/rev/660a95371114ac87ed1f171513cfaa3ca4aab9c8
Log link: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=281704454&repo=autoland&lineNumber=3963

There were also dt failures on browser_dbg-browser-content-toolbox.js
Log link: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=281702993&repo=autoland&lineNumber=3909

For browser_aboutdebugging_process_main.js , the test is checking the text of the Main Process item.
I think it's fair to add await pushPref("devtools.browsertoolbox.fission", false); at the beginning of the test for this one.

Ignore worker targets in the console as we workerTarget.getFront("console") fails.
It relates to bug 1592584 and properly support workers by using a real console actor
rather than piping the console message via platform API to the main thread.

https://hg.mozilla.org/mozilla-central/rev/721fefd09f16

Added to the final Fx73 relnotes.