Add WPT for error events during event dispatch when multiple globals exist
See also whatwg/dom#1303
Change-Id: Ie54cb8204e41d9e4ba1b972d297a8b43f45585ad
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5784046
Reviewed-by: Mason Freed masonf@chromium.org
Commit-Queue: Jeremy Roman jbroman@chromium.org
Cr-Commit-Position: refs/heads/main@{#1342638}