Постоянная DOM_DELTA_PIXEL
Реализация
static const int DOM_DELTA_PIXEL = 0x00;
© 2012 the Dart project authors
Licensed under the BSD 3-Clause "New" or "Revised" License.
https://api.dart.dev/stable/2.18.5/dart-html/WheelEvent/DOM_DELTA_PIXEL-constant.html
