roundRect might be better as an extension to CanvasPath mixin

[Kaiido]

The current proposal makes CanvasRoundRect about the same interface as CanvasRect, but I don't see the rationale for this choice.

As a web author I would prefer to have a roundRect() extension to the CanvasPath mixin, allowing to store it in Path2D objects maybe along with other shapes, or use it with methods like clip, isPointIn..., scrollToPath etc. and also allowing to fill or stroke many such shapes in a single call (with non negligible performance improvements).

I don't really see the point of having it outside of the "current path" and having an other method to clear pixels doesn't seem really useful either (we can already use compositing + fill() to clear from any path).

[fserb]

cc @mysteryDate

[mysteryDate]

This seems totally reasonable to me. I'll see if there are objections on whatwg.

[Kaiido]

I believe #8 handled it, closing this.