cherry-pick: fix edge swiping and dropping back at starting point (#31623)
iOS selection handles are invisible (#31332) (#31862)
Fix a bug where text selection handles were invisible in iOS
Pick up engine with dart sdk cherry-picks (#31871)
Cherry pick CrOS fix to beta (#31835)
This cherry-picks fdcc8aafa75eb44ae7732debac1bd8db786c3b9a into the current beta branch. There was a trivial conflict because new tests were added on master in the same file, so the last lines before the tests were different.