anchor.diff:    @override
     void ngOnDestroy() {
       super.ngOnDestroy();
  +    _subscription?.cancel();
  +    _subscription = null;
       textareaEl = null;
       popupSourceEl = null;
     }
  
positive.code:       var height = (value.nativeElement as Element).clientHeight;
        if (height != 0) {
          _inputLineHeight = height;
          _changeDetector
            ..markForCheck()
            // TODO(google): remove after the bug is fixed.
            ..detectChanges();
        }
      });
    }
  
negative.code: // for details. All rights reserved. Use of this source code is governed by a
  // BSD-style license that can be found in the LICENSE file.
  
  import 'dart:async';
  import 'dart:html';
  
  import 'package:angular/angular.dart';
  