window.scrollBy misses checking the type of options param

[[e-mail]]

Steps to reproduce:

(1) Open a tab and navigate to any URL;
(2) Open Devtools and run the following code in the Console:
```
window.scrollBy('\u{1a}');
```

Actual results:

This code would be evaluated successfully without any exceptions thrown.

Expected results:

As https://drafts.csswg.org/cssom-view/#dom-window-scrollby says, the param should be of ScrollToOptions type. Thus a TypeError exception should be thrown for this code.

In my test, both Chrome and Firefox would throw exceptions:
Chrome: `TypeError: Failed to execute 'scrollBy' on 'Window': cannot convert to dictionary.`
Firefox: `Window.scrollBy: Value can't be converted to a dictionary.`

[Chris Dumez]

window.scrollBy('\u{1a}'); gives me a TypeError on Safari 15. This is likely already fixed.

[Chris Dumez]

(In reply to Chris Dumez from comment #1)
> window.scrollBy('\u{1a}'); gives me a TypeError on Safari 15. This is likely
> already fixed.

I recommend trying Safari Technology Preview or Safari 15 beta.