Add a WPT for coalesced event attributes on redispatch.
The test is tentative due to:
w3c/pointerevents#514
Bug: 353538500
Change-Id: Id3ead2029e84a3100573558adbd7c14c272e821f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5823713
Reviewed-by: Robert Flack flackr@chromium.org
Commit-Queue: Mustaq Ahmed mustaq@chromium.org
Cr-Commit-Position: refs/heads/main@{#1350816}