[CP] Avoid animation jank by setting FlutterViewController backgroundColor to clearColor (beta) #120139
Description
issue_link
Commit Hash
Target
beta
Stable CP request at #120130
pr_link
flutter/engine#39436 (that is off stable, will make a beta PR after it branches)
Impacted Users
iOS end users on high-end iPhones
Impact Description
On certain iPhones (iPhone 13 and 14 Pro, Pro Max) iOS apps are janky. This very simple one-line fix seems to resolve it on these devices.
Workaround
No.
Risk
low
Test Coverage
yes
Validation Steps
Run a Flutter app with a scrolling list view on an iPhone 13/14 Pro/Pro Max and scroll to see jank. On this fix scrolling is smooth.