Update pubspecs and dependencies to get pkgbuild tests working.

third_party/pkg/angular/demo/todo/web/main.dart

-import 'package:di/di.dart';
-import 'package:angular/angular.dart';
-import 'package:angular/playback/playback_http.dart';
-import 'todo.dart';
-
-import 'dart:html';
-
-// Everything in the 'todo' library should be preserved by MirrorsUsed.
-@MirrorsUsed(
-    targets: const ['todo'],
-    override: '*')
-import 'dart:mirrors';
-
-main() {
-  print(window.location.search);
-  var module = new Module()
-      ..type(TodoController)
-      ..type(PlaybackHttpBackendConfig);
-
-  // If these is a query in the URL, use the server-backed
-  // TodoController.  Otherwise, use the stored-data controller.
-  var query = window.location.search;
-  if (query.contains('?')) {
-    module.type(ServerController, implementedBy: HttpServerController);
-  } else {
-    module.type(ServerController, implementedBy: NoServerController);
-  }
-
-  if (query == '?record') {
-    print('Using recording HttpBackend');
-    var wrapper = new HttpBackendWrapper(new HttpBackend());
-    module.value(HttpBackendWrapper, new HttpBackendWrapper(new HttpBackend()));
-    module.type(HttpBackend, implementedBy: RecordingHttpBackend);
-  }
-
-  if (query == '?playback') {
-    print('Using playback HttpBackend');
-    module.type(HttpBackend, implementedBy: PlaybackHttpBackend);
-  }
-
-  ngBootstrap(module: module);
-}