Add WPT for error reporting during custom element upgrade
This test currently fails in Chromium. 3/4 subtests fail with:
error event should target definition's global but instead
targets test harness global"
See also: whatwg/dom#1303
Bug: 359909516
Change-Id: I0cc589735d9f8c8ec2c4b55c89aabdb4f7500e17
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5789341
Commit-Queue: Jeremy Roman jbroman@chromium.org
Reviewed-by: Mason Freed masonf@chromium.org
Cr-Commit-Position: refs/heads/main@{#1342635}