While switching all client to fronts, we will no longer manipulate actor IDs and instead always call requests through their front instance.

Scratchpad

Scratchpad seems to use it exclusively from the variablesview: https://searchfox.org/mozilla-central/search?q=releaseActor&case=false&regexp=false&path=scratchpad

VariableView

https://searchfox.org/mozilla-central/rev/b36e97fc776635655e84f2048ff59f38fa8a4626/devtools/client/shared/widgets/VariablesViewController.jsm#573

Like in other places, it appears that this collection only exists in order to release the actors.

I'm not sure I follow this bug correctly, but it looks like it is still relevant as the storage panel is still using the VariableView
and there is still a releaseActor method in it:
https://searchfox.org/mozilla-central/source/devtools/client/shared/widgets/VariablesViewController.jsm#727-738

VariablesViewController doesn't look to be used anywhere now, so I'm going to remove it and repurpose this bug to do so, since the VariablesView does not call any release function (and Scratchpad was removed).

It isn't used anywhere, so we can safely remove it.

Backed out for build bustages on storage/moz.build

Backout link: https://hg.mozilla.org/integration/autoland/rev/ad5a005cee3ed9d6f883dc8312cc8fd24dce28b3
Log link: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=279272756&repo=autoland&lineNumber=1280

Backed out 2 changesets (Bug 1529917, Bug 1591874) for causing bustages in VariablesView.jsm

Backout link: https://hg.mozilla.org/integration/autoland/rev/4cf52729f132bf19c9465044d4f0e14b9cca25de

Push with failures: https://treeherder.mozilla.org/#/jobs?repo=autoland&collapsedPushes=598800&tochange=4cf52729f132bf19c9465044d4f0e14b9cca25de&fromchange=0b5282256e0094eeae41d6c6377c6b37893cbf06&selectedJob=279319506

Failure log: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=279319506&repo=autoland&lineNumber=1390

[task 2019-12-03T13:23:07.427Z] 13:23:07 INFO - mozbuild.frontend.reader.SandboxValidationError:
[task 2019-12-03T13:23:07.427Z] 13:23:07 INFO - ==============================
[task 2019-12-03T13:23:07.427Z] 13:23:07 INFO - FATAL ERROR PROCESSING MOZBUILD FILE
[task 2019-12-03T13:23:07.427Z] 13:23:07 INFO - ==============================
[task 2019-12-03T13:23:07.427Z] 13:23:07 INFO - The error occurred while processing the following file or one of the files it includes:
[task 2019-12-03T13:23:07.427Z] 13:23:07 INFO - /builds/worker/workspace/build/src/devtools/client/storage/moz.build
[task 2019-12-03T13:23:07.427Z] 13:23:07 INFO - The error occurred when validating the result of the execution. The reported error is:
[task 2019-12-03T13:23:07.427Z] 13:23:07 INFO - File listed in FINAL_TARGET_FILES does not exist: /builds/worker/workspace/build/src/devtools/client/storage/VariablesView.jsm

Backed out 2 changesets (Bug 1529917, Bug 1591874) for ESlint failure on VariablesView.jsm.
https://hg.mozilla.org/integration/autoland/rev/15c693744f0c3e65ea3f60831f816e836741b753

Push with failures:
https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=pending%2Crunning%2Csuccess%2Ctestfailed%2Cbusted%2Cexception&revision=a7f97f586d04b2063c1d4efc41ea043c7e275ec1&selectedJob=279364277

Failure log: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=279364277&repo=autoland&lineNumber=54

There was an issue with Lando (see Bug 1600990).

https://hg.mozilla.org/mozilla-central/rev/f6b30c89d279