* Migrate to python3; drop python support.
* Update Windows toolchain support.
* Remove some unused methods.
* Python 2.7 is still needed on Windows.
* Update gsutil to a version that supports python3.
Fixes: https://github.com/dart-lang/sdk/issues/28793
TEST=Manually tested common user journeys.
Change-Id: I663a22b237a548bb82dc2e601e399e3bc3649211
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/192182
Reviewed-by: William Hesse <whesse@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
- Add `.style.yapf` with configuration to use Google style.
- Run `yapf` on all `.py` files in this repo.
- Manually fix one trailing space in a doc string.
- Run `git cl format runtime` to satisfy presubmit.
Change-Id: I7e6bd11e91f07926b9188362599af398551eed79
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/111600
Commit-Queue: Nate Bosch <nbosch@google.com>
Reviewed-by: Alexander Thomas <athom@google.com>
