[cp:beta][web] Work around wrong pointerId in coalesced events in iOS Safari 18.2 #159692
Description
Issue Link
Target
beta
Cherry pick PR Link
Changelog Description
Manual cherrypick to workaround a pointer/gesture bug in iOS 18.2 Safari.
Impacted Users
Users on iOS 18.2
Impact Description
The most obvious impact is scrolling. In iOS 18.2, Flutter Web don't scroll. Other gestures may also be impacted, but scrolling is the most obvious one.
Workaround
This cherrypick is the workaround :) Unfortunately, there's nothing users can do to workaround this iOS bug.
Risk
low
Test Coverage
yes
Validation Steps
No response