chore: remove obsolete files (#10240)

modules/@angular/common/src/directives/observable_list_diff.dart

@@ -1,63 +0,0 @@
-library angular2.directives.observable_list_iterable_diff;
-
-import 'package:observe/observe.dart' show ObservableList;
-import 'package:angular2/core.dart';
-import 'package:angular2/src/core/change_detection/differs/default_iterable_differ.dart';
-import 'dart:async';
-
-class ObservableListDiff extends DefaultIterableDiffer {
-  ChangeDetectorRef _ref;
-  ObservableListDiff(this._ref);
-
-  bool _updated = true;
-  ObservableList _collection;
-  StreamSubscription _subscription;
-
-  onDestroy() {
-    if (this._subscription != null) {
-      this._subscription.cancel();
-      this._subscription = null;
-      this._collection = null;
-    }
-  }
-
-  DefaultIterableDiffer diff(ObservableList collection) {
-    if (collection is! ObservableList) {
-      throw "Cannot change the type of a collection";
-    }
-
-    // A new collection instance is passed in.
-    // - We need to set up a listener.
-    // - We need to diff collection.
-    if (!identical(_collection, collection)) {
-      _collection = collection;
-
-      if (_subscription != null) _subscription.cancel();
-      _subscription = collection.changes.listen((_) {
-        _updated = true;
-        _ref.markForCheck();
-      });
-      _updated = false;
-      return super.diff(collection);
-
-      // An update has been registered since the last change detection check.
-      // - We reset the flag.
-      // - We diff the collection.
-    } else if (_updated) {
-      _updated = false;
-      return super.diff(collection);
-
-      // No updates has been registered.
-    } else {
-      return null;
-    }
-  }
-}
-
-class ObservableListDiffFactory implements IterableDifferFactory {
-  const ObservableListDiffFactory();
-  bool supports(obj) => obj is ObservableList;
-  IterableDiffer create(ChangeDetectorRef cdRef, [Function trackByFn]) {
-    return new ObservableListDiff(cdRef);
-  }
-}