Dispatch BeforeInput Event for number input spin button and Arrow key
https://w3c.github.io/uievents/#event-type-beforeinput
A user agent MUST dispatch beforeinput event when the DOM is about to be updated.
Bug: 40948436
Change-Id: Idc894f4e7427a81e684b37cc10749b4386e5aa7d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5443103
Reviewed-by: Mason Freed masonf@chromium.org
Commit-Queue: Utkarsh Pathak utpathak@microsoft.com
Reviewed-by: Sanket Joshi sajos@microsoft.com
Reviewed-by: Anupam Snigdha snianu@microsoft.com
Cr-Commit-Position: refs/heads/main@{#1308524}