anchor.diff:  ///  * https://www.w3.org/TR/webcodecs/#imagedecoderesult-interface
   @JS()
   @anonymous
  -class DecodeResult {
  +@staticInterop
  +class DecodeResult {}
  +
  +extension DecodeResultExtension on DecodeResult {
     external VideoFrame get image;
     external bool get complete;
   }
  
positive.code: /// [Future] API.
  @JS()
  @anonymous
  class JsPromise {}
  
  /// Corresponds to the browser's `ImageDecoder` type.
  
negative.code: ///  * https://www.w3.org/TR/webcodecs/#imagetrack
  @JS()
  @anonymous
  @staticInterop
  class ImageTrack {}
  
  extension ImageTrackExtension on ImageTrack {
    external int get repetitionCount;
    external int get frameCount;
  }
  