* Revert "unnecessary this in field initializers (#22522)" This reverts commit5de96bb734. * Revert "Use unsafePackageSerialization when running tests (#22407)" This reverts commit4bd6ad7395. * Revert "Roll engine f6af1f20ba92..b59c86493159 (3 commits) (#22538)" This reverts commit85a4591aa3.
Dart SDK dependency
The bin/internal/engine.version file controls which version of the Flutter engine to use.
The file contains the commit hash of a commit in the https://github.com/flutter/engine repository.
That hash must have successfully been compiled on https://build.chromium.org/p/client.flutter/ and had its artifacts (the binaries that run on Android and iOS, the compiler, etc) successfully uploaded to Google Cloud Storage.