1300238 - Is there anyway to see when an unsafe/forbidden CPOW is used by an add-on

Status: RESOLVED FIXED

(Firefox :: Extension Compatibility, defect, P1)

Description

[:shell escalante]

Is there an error, anything in telemetry, or any probe that could be added when an unsafe/forbidden CPOW is used?  how is it exposed?  what is the result?

Comment 1

[:shell escalante]

i don't know enough about the browser console to make an intelligent connection to if this is accessible - but apparently you can see the following type error in the browser console:

unsafe CPOW usage forbidden
continueSave()                  contentAreaUtils.js:464
internalSave/<()                contentAreaUtils.js:444
Handler.prototype.process()     Promise-backend.js:937
this.PromiseWalker.walkerLoop() Promise-backend.js:816
bound ()                        self-hosted
bound bound ()                  self-hosted

contentAreaUtils.js:464 is the 4th line here:
    let isPrivate = aIsContentWindowPrivate;
    if (isPrivate === undefined) {
      isPrivate = aInitiatingDocument instanceof Components.interfaces.nsIDOMDocument
        ? PrivateBrowsingUtils.isContentWindowPrivate(aInitiatingDocument.defaultView)
        : aInitiatingDocument.isPrivate;
    }

Comment 2

[:shell escalante]

Reason - if we can do something - running Beta we could see add-ons where shims are still going to break in production and make sure we do not enable e10s for them or we make them stop running.  either way - we could greatly preserve the user experience.

just running through options: https://docs.google.com/document/d/1WP__6Uo-jQwF6cnz0YtqslG9_z1Tf43ADYKELmGiaDI/edit

Comment 3

[Dave Zeber [:dzeber]]

There is the keyed histogram ADDON_FORBIDDEN_CPOW_USAGE which "counts the number of times a given add-on used CPOWs when it was marked as e10s compatible" (https://dxr.mozilla.org/mozilla-central/source/toolkit/components/telemetry/Histograms.json#46). It was added as a part of Bug 1214824.

Comment 4

[:shell escalante]

this was worked through