44610 Error Message for createState assertion

38814 Add iOS backdrop filter benchmarks

38821 Cache caret parameters

38861 Replace deprecated onReportTimings w/ frameTimings

39439 Measure iOS CPU/GPU percentage

43676 Allow multiple TimingsCallbacks

45050 Add a perf test for picture raster cache

New features

Flutter 1.12 introduces several new features including the
SliverOpacity
widget, the
SliverAnimatedList,
and the ability to configure a stretch effect for a SliverAppBar.

37416 Add MediaQuery.systemGestureInsets to support Android Q

39857 Update ToggleButtons constraints default and add new constraints parameter

40161 Add fullscreenDialog argument in PageRouteBuilder