Add types on overridden method signatures
Add types on overridden method signatures

We were inconsistent about using return and argument types with
overridden methods. It is technically safe to omit them since they'll be
inferred from the super class - but it's more explicit and readable to
repeat them here. We were already using types on some of the overrides -
add them to the remainder.

Change-Id: Id8529e40a80c8ff3d5feb231a37a12d3d6487b4d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/104160
Reviewed-by: Nicholas Shahan <03847abd2d8aadfe859ecb98095a31f9f515dc47@google.com>
Commit-Queue: Nate Bosch <dc212c74d8afde9c690fdd09e74d3e5c5d5a3de0@google.com>

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