Fix snap fling regression
In the linked bug, flings within large snap areas (constrained native
flings) would incorrectly snap based on the last finger position,
rather than the position the fling lands at.
This patch fixes this by ensuring that we always recompute the snap
strategy for a constrained native fling since we cannot know ahead of
time where that fling will land.
Bug: 340895249
Change-Id: I53dd98238a8ce574f552ccace4ee40427248b9cd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5555100
Reviewed-by: Robert Flack flackr@chromium.org
Commit-Queue: David Awogbemila awogbemila@chromium.org
Cr-Commit-Position: refs/heads/main@{#1308128}