DOM: Support atomic moves across shadow boundary
Per discussion with DOM editors, we've resolved to enable this
functionality.
Bug: 40150299
Change-Id: I9bdb577c7538ca9cfe7af95b6c66159ade8e0c72
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5891771
Reviewed-by: Noam Rosenthal nrosenthal@chromium.org
Commit-Queue: Dominic Farolino dom@chromium.org
Cr-Commit-Position: refs/heads/main@{#1360104}