Re: [streams] Port locking infrastructure to writable streams (#319)

Plan:

```js
class WritableStream {
  constructor(underlyingSink = {}, { size, highWaterMark = 0 } = {})
  
  get locked()

  getWriter()
  abort(reason)
  close()
}

class WritableStreamWriter {
  constructor(stream)
  
  get closed()
  get ready() // see #318

  abort(reason)
  close()
  releaseLock()
  write(chunk)
}
```

No need for WritableStreamController. Can eliminate `error` parameter to underlying sink `start()`.


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Reply to this email directly or view it on GitHub:
https://github.com/whatwg/streams/issues/319#issuecomment-133150569