Change ChildNodePart comment nodes from "S"/"E" to "#" and "/"
This better matches the declarative HTML syntax, which is:
{{#}} child nodes {{/}}
No real functional change, since typical usage doesn't examine the
content of these comments.
Bug: 40271855
Change-Id: Id2a4da2ee22b34e04dca2e4adca7bcacb57e5207
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5640573
Auto-Submit: Mason Freed masonf@chromium.org
Reviewed-by: Joey Arhar jarhar@chromium.org
Commit-Queue: Joey Arhar jarhar@chromium.org
Cr-Commit-Position: refs/heads/main@{#1317945}