I figured out that there is a cleaner way to load from disk that doesn't lose
the null-ness of results. This was causing UI issues across restarts.

This is entirely behind a pref still, but having a prototype for consumers to play with
sooner than UI/UX review will be good.

Depends on D215005

Down the stack I need to change the argument to notify in the nsICredentialChosenCallback so it
can run in Javascript for testing. I make the change here that allows consumers of this class to
still get the IPCIdentityCredential in the resolve callback of the argument promise.

Depends on D215006

This is the meat of the chooser's logic.

Depends on D215007

I'm sorry. This is a big change to recent stuff, and worst of all is a big commit.

Decisions I made while implementing credential discovery backed me into a corner
where I couldn't have the UI actually get rendered. Particularly around where the
IPCs needed to happen and at what point we called into the main process and when
we returned.

The way it works now is that we do ONE IPC for a credentials.get call, doing most of
the work in the main process and only maybe doing one IPC down to the content process
to tell it to navigate.

This is neater and more secure to a compromised content process. However, a lot happens in
this patch.

Depends on D215008

Depends on D215009

Depends on D215010

Backed out for causing build bustages in credentialChooser.ftl.

• Backout link
• Push with failures
• Failure Log
• Failure line: RuntimeError: File "../../toolkit/components/credentialmanagement/credentialChooser.ftl" not found in /builds/worker/checkouts/gecko/browser/locales, /builds/worker/workspace/obj-build/browser/locales

Also, please check these bp-nu bustages too.

• Failure Log

L.E. Please also check these wpt failures.

• Failure Log

Case sensitivity strikes macos user. Fixing other bustage and faulure too.

Backed out for causing mochitest failures related to browser_credential_chooser.js

• Backout link
• Push with failures
• Failure Log:

[task 2024-07-24T20:38:38.634Z] 20:38:38     INFO - TEST-START | toolkit/components/credentialmanagement/tests/browser/browser_credential_chooser.js
[task 2024-07-24T20:38:38.658Z] 20:38:38     INFO - GECKO(8609) | [Child 8957: Main Thread]: I/DocShellAndDOMWindowLeak ++DOCSHELL 7f7a76d63400 == 1 [pid = 8957] [id = 0]
[task 2024-07-24T20:38:38.658Z] 20:38:38     INFO - GECKO(8609) | [Child 8957: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 1 (7f7a94df3a00) [pid = 8957] [serial = 1] [outer = 0]
[task 2024-07-24T20:38:38.660Z] 20:38:38     INFO - GECKO(8609) | [Child 8957: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 2 (7f7a76d63c00) [pid = 8957] [serial = 2] [outer = 7f7a94df3a00]
[task 2024-07-24T20:38:38.855Z] 20:38:38     INFO - GECKO(8609) | [Parent 8609, Main Thread] WARNING: BounceTrackingState::OnDocumentStartRequest failed.: 'NS_SUCCEEDED(rv)', file /builds/worker/checkouts/gecko/netwerk/ipc/DocumentLoadListener.cpp:2618
[task 2024-07-24T20:38:38.872Z] 20:38:38     INFO - GECKO(8609) | [Child 8957: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 3 (7f7a76d66c00) [pid = 8957] [serial = 3] [outer = 7f7a94df3a00]
[task 2024-07-24T20:38:39.018Z] 20:38:39     INFO - GECKO(8609) | [WARN  l10nregistry_ffi::env] L10nRegistry error: Missing resource in locale en-US: preview/CredentialChooser.ftl
[task 2024-07-24T20:38:39.019Z] 20:38:39     INFO - GECKO(8609) | [fluent] Couldn't find a message: credential-chooser-sign-in-button
[task 2024-07-24T20:38:39.020Z] 20:38:39     INFO - GECKO(8609) | [fluent] Couldn't find a message: credential-chooser-cancel-button
[task 2024-07-24T20:38:39.038Z] 20:38:39     INFO - GECKO(8609) | JavaScript error: , line 0: InvalidStateError: [fluent] Couldn't find a message: credential-chooser-sign-in-button
[task 2024-07-24T20:38:39.766Z] 20:38:39     INFO - GECKO(8609) | ### XPCOM_MEM_BLOAT_LOG defined -- logging bloat/leaks to /tmp/tmpqbsr9x0z.mozrunner/runtests_leaks_tab_pid9067.log
[task 2024-07-24T20:38:39.789Z] 20:38:39     INFO - GECKO(8609) | [Child 9067, Main Thread] WARNING: could not set real-time limit in CubebUtils::InitLibrary: file /builds/worker/checkouts/gecko/dom/media/CubebUtils.cpp:757
[task 2024-07-24T20:38:40.922Z] 20:38:40     INFO - GECKO(8609) | [Child 8669: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 17 (7ff1e4a72800) [pid = 8669] [serial = 6] [outer = 0] [url = about:blank]
[task 2024-07-24T20:38:40.922Z] 20:38:40     INFO - GECKO(8609) | [Child 8669: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 16 (7ff1e4a6f400) [pid = 8669] [serial = 2] [outer = 0] [url = about:blank]
[task 2024-07-24T20:38:40.922Z] 20:38:40     INFO - GECKO(8609) | [Child 8669: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 15 (7ff1e4a74800) [pid = 8669] [serial = 10] [outer = 0] [url = about:blank]
[task 2024-07-24T20:38:40.922Z] 20:38:40     INFO - GECKO(8609) | [Child 8669: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 14 (7ff1e4a73800) [pid = 8669] [serial = 8] [outer = 0] [url = about:blank]
[task 2024-07-24T20:38:40.922Z] 20:38:40     INFO - GECKO(8609) | [Child 8669: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 13 (7ff1e4a71000) [pid = 8669] [serial = 4] [outer = 0] [url = about:blank]
[task 2024-07-24T20:38:40.922Z] 20:38:40     INFO - GECKO(8609) | [Child 8669: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 12 (7ff1e3885c00) [pid = 8669] [serial = 17] [outer = 0] [url = about:blank]
[task 2024-07-24T20:38:41.951Z] 20:38:41     INFO - GECKO(8609) | [Child 8719: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 4 (7f0b80161800) [pid = 8719] [serial = 4] [outer = 0] [url = about:blank]
[task 2024-07-24T20:38:41.953Z] 20:38:41     INFO - GECKO(8609) | [Child 8719: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 3 (7f0b8015d800) [pid = 8719] [serial = 3] [outer = 0] [url = about:blank]
[task 2024-07-24T20:38:41.953Z] 20:38:41     INFO - GECKO(8609) | [Child 8719: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 2 (7f0b8015c000) [pid = 8719] [serial = 2] [outer = 0] [url = about:blank]
[task 2024-07-24T20:38:42.525Z] 20:38:42     INFO - GECKO(8609) | [Parent 8609: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 11 (7ff0077e8c00) [pid = 8609] [serial = 4] [outer = 0] [url = about:blank]
[task 2024-07-24T20:38:42.532Z] 20:38:42     INFO - GECKO(8609) | [Parent 8609: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 10 (7ff001ee1400) [pid = 8609] [serial = 9] [outer = 0] [url = about:blank]
[task 2024-07-24T20:38:42.914Z] 20:38:42     INFO - GECKO(8609) | [Child 8785: Main Thread]: I/DocShellAndDOMWindowLeak --DOCSHELL 7f8556b67800 == 0 [pid = 8785] [id = 0] [url = about:blank]
[task 2024-07-24T20:38:42.924Z] 20:38:42     INFO - GECKO(8609) | [Child 8785: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 1 (7f8556257200) [pid = 8785] [serial = 1] [outer = 0] [url = about:blank]
[task 2024-07-24T20:38:44.259Z] 20:38:44     INFO - GECKO(8609) | [Child 8834: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 2 (7fb40366b800) [pid = 8834] [serial = 2] [outer = 0] [url = about:blank]
[task 2024-07-24T20:38:47.118Z] 20:38:47     INFO - GECKO(8609) | [Child 8785: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 0 (7f8556b68000) [pid = 8785] [serial = 2] [outer = 0] [url = about:blank]
[task 2024-07-24T20:38:51.169Z] 20:38:51     INFO - GECKO(8609) | [Child 8957: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 2 (7f7a76d63c00) [pid = 8957] [serial = 2] [outer = 0] [url = about:blank]
[task 2024-07-24T20:39:07.114Z] 20:39:07     INFO - GECKO(8609) | [Child 8669: Main Thread]: I/DocShellAndDOMWindowLeak --DOCSHELL 7ff1e4a73400 == 5 [pid = 8669] [id = 3] [url = moz-extension://822636b6-d278-413e-9c1e-48fae0bf5684/_generated_background_page.html]
[task 2024-07-24T20:39:11.258Z] 20:39:11     INFO - GECKO(8609) | [Child 8669: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 11 (7ff1e4254800) [pid = 8669] [serial = 7] [outer = 0] [url = moz-extension://822636b6-d278-413e-9c1e-48fae0bf5684/_generated_background_page.html]
[task 2024-07-24T20:39:15.329Z] 20:39:15     INFO - GECKO(8609) | [Child 8669: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 10 (7ff1e387d400) [pid = 8669] [serial = 14] [outer = 0] [url = moz-extension://822636b6-d278-413e-9c1e-48fae0bf5684/_generated_background_page.html]
[task 2024-07-24T20:40:08.717Z] 20:40:08     INFO - TEST-INFO | started process screentopng
[task 2024-07-24T20:40:08.998Z] 20:40:08     INFO - TEST-INFO | screentopng: exit 0
[task 2024-07-24T20:40:09.007Z] 20:40:09     INFO - Buffered messages logged at 20:38:38
[task 2024-07-24T20:40:09.007Z] 20:40:09     INFO - Entering test bound test_single_credential_dialog
[task 2024-07-24T20:40:09.007Z] 20:40:09     INFO - Buffered messages logged at 20:38:39
[task 2024-07-24T20:40:09.007Z] 20:40:09     INFO - Console message: [JavaScript Warning: "Missing resource in locale en-US: preview/CredentialChooser.ftl"]
[task 2024-07-24T20:40:09.007Z] 20:40:09     INFO - Console message: [JavaScript Warning: "[fluent] Couldn't find a message: credential-chooser-sign-in-button"]
[task 2024-07-24T20:40:09.007Z] 20:40:09     INFO - Console message: [JavaScript Warning: "[fluent] Couldn't find a message: credential-chooser-cancel-button"]
[task 2024-07-24T20:40:09.007Z] 20:40:09     INFO - Console message: [JavaScript Error: "InvalidStateError: [fluent] Couldn't find a message: credential-chooser-sign-in-button"]
[task 2024-07-24T20:40:09.007Z] 20:40:09     INFO - Buffered messages finished
[task 2024-07-24T20:40:09.007Z] 20:40:09     INFO - TEST-UNEXPECTED-FAIL | toolkit/components/credentialmanagement/tests/browser/browser_credential_chooser.js | Test timed out - 
[task 2024-07-24T20:40:09.007Z] 20:40:09     INFO - GECKO(8609) | Completed ShutdownLeaks collections in process 8609
[task 2024-07-24T20:40:09.007Z] 20:40:09     INFO - TEST-START | Shutdown

Backed out for causing bc failures on browser_credential_chooser.js

Backout link

Push with failures

Failure log

Wpt failures are also present with these failure lines: https://treeherder.mozilla.org/logviewer?job_id=467957577&repo=autoland&lineNumber=6670

Backed out for causing failures at browser_credential_chooser.js.

Backout link: https://hg.mozilla.org/integration/autoland/rev/e98ebc60c618c5aa9cc3ba9a5aa90ef169d0668f

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception%2Cretry%2Cusercancel&revision=7e08bac9cd1b2945cfa20f61d978738accf7cb11&selectedTaskRun=AxciEB6sR9qrUDjp-lmqnQ.0

Failure log:
https://treeherder.mozilla.org/logviewer?job_id=467990171&repo=autoland&lineNumber=12351
https://treeherder.mozilla.org/logviewer?job_id=467991615&repo=autoland&lineNumber=1807

Ah, I've realized my problem with that test. It was fixed later down the stack. Pushing the whole lot, since it passes:

https://treeherder.mozilla.org/jobs?repo=try&resultStatus=testfailed%2Cbusted%2Cexception&classifiedState=unclassified&tier=1&revision=f716befdbf743cd44403160d8cbbc7099d0058f3

https://hg.mozilla.org/mozilla-central/rev/eba8ce6b348f
https://hg.mozilla.org/mozilla-central/rev/72b108bb7c3a
https://hg.mozilla.org/mozilla-central/rev/5f8a5419d394
https://hg.mozilla.org/mozilla-central/rev/7eb447f12cd9
https://hg.mozilla.org/mozilla-central/rev/b69c4cf25381
https://hg.mozilla.org/mozilla-central/rev/98cf6e5c1549
https://hg.mozilla.org/mozilla-central/rev/cb0b1184c972