Update checked-in Windows SDK to 2.0.0-dev.63.0
Update checked-in Windows SDK to 2.0.0-dev.63.0

Linux and Mac SDKs will be updated in a follow-up commit.

Change-Id: I23277bce01257409c8a8634ea5dbe58981f76bf1
Reviewed-on: https://dart-review.googlesource.com/60460
Reviewed-by: Bob Nystrom <afede3a9ebedb865bee78398feff6fbe97068f17@google.com>

dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk