How to fix "Audion could not identify the object calling 'connect'" error when trying to run AudioContext.createMediaElementSource()?
The warning is coming from a Chrome extension which is officially called Web Audio Inspector. It's codename is Audion. The source code is available on GitHub. The warning message get's generated here: https://github.com/google/audion/blob/master/js/entry-points/tracing.js#L747
I think the problem is that Audion still patches the prototype of the BaseAudioContext but a recent change in the spec moved functions like createMediaElementSource() to the AudioContext prototype. I will go ahead and create an issue for that on GitHub which will hopefully get fixed at some point.
That being said, it's just a warning and it should not stop your website from working correctly.