(just animation, foundation, and widget_previews)
Work towards https://github.com/dart-lang/sdk/issues/61597
Work towards https://github.com/dart-lang/sdk/issues/61943
In this CL, I try to keep the elements generally the same as they
are in `pkg/analyzer_testing/lib/mock_packages/package_content/flutter`
and only correcting things that are wrong/out of date. To that end:
* AnimationController extends Animation, which is defined in
`lib/src/animation/animation.dart`, so we add that.
* FlutterErrorDetails.new has many more parameters.
* Listenable and ValueListenable are necessary, so those are added in
`lib/src/foundation/change_notifier.dart`.
* There is no `Key._` constructor, but there is now `Key.empty`.
* Preview no longer has a `width` or `height` property (or constructor
parameter) but now has `size`.
Change-Id: I7e73d26e6fdf9896b24e1d908f0bf2950f67db16
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/465660
Commit-Queue: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Sam Rawlins
c5b86a3dd8