registerPaint() behavior is unclear #232
Description
From @bzbarsky: 'registerPaint adds things to a map on the document. But registerPaint is expected to be called once per worklet. So once you have more than one worklet, you will have multiple entries in the document's map with the same key. I have no idea what is expected to happen in this case, especially when the values are different. I think the spec wanted to have a check for this, but since this spec is pretty undecided about which object the "paint name to paint image definition map" lives (WorkletGlobalScope, or document), in practice the checks fails.'
It also seems to me that this crosses the thread boundary that's supposed to exist.