We found a discrepancy between IDL and implementation in blink where RTCRtpScriptTransformer was not actually implementing EventTarget, even though it extended EventTarget per IDL. We opted for removing the base from the IDL, given no events are actually dispatched on it, any prior attempt to add an event listener or dispatch an event from JS would have resulted in a problem, and other implementations do not appear to be inheriting from EventTarget either (see link below for details).
I'm filing per discussion in https://chromium-review.git.corp.google.com/c/chromium/src/+/7740681 for the spec authors to consider removing EventTarget base from the spec as well.
We found a discrepancy between IDL and implementation in blink where RTCRtpScriptTransformer was not actually implementing EventTarget, even though it extended EventTarget per IDL. We opted for removing the base from the IDL, given no events are actually dispatched on it, any prior attempt to add an event listener or dispatch an event from JS would have resulted in a problem, and other implementations do not appear to be inheriting from EventTarget either (see link below for details).
I'm filing per discussion in https://chromium-review.git.corp.google.com/c/chromium/src/+/7740681 for the spec authors to consider removing EventTarget base from the spec as well.