Chrome historically allowed creation of MediaElementAudioSourceNode's, MediaStreamAudioSourceNode's, and MediaStreamAudioDestinationNode's using an OfflineAudioContext. This does not comply with the spec; these nodes should only be available for an AudioContext. The behavior with an OfflineAudioContext is not well-defined and contrary to the real-time nature of the nodes themselves. Thus, only allow these nodes to be constructed for an AudioContext.
Docs: https://webaudio.github.io/web-audio-api/#mediaelementaudiosourcenode https://webaudio.github.io/web-audio-api/#mediastreamaudiosourcenode https://webaudio.github.io/web-audio-api/#mediastreamtrackaudiosourcenode https://webaudio.github.io/web-audio-api/#mediastreamaudiodestinationnode