Forward SetScrollsnapchangeTargetIds to LayoutViewport()
The RootFrameViewport did not implement forwarding of
SetScrollsnapchangeTargetIds to the LayoutViewport() which meant
triggering snapchange did not always work correctly. Specifically, a
change in scroll-snap-type did not trigger the event.
Bug: 364466903
Change-Id: I97fdd02a72dace4e74bc7fbf03f08fd396e87ba9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5830358
Reviewed-by: Kevin Ellis kevers@chromium.org
Reviewed-by: David Awogbemila awogbemila@chromium.org
Commit-Queue: Rune Lillesveen futhark@chromium.org
Cr-Commit-Position: refs/heads/main@{#1350940}