TickerProvider vsync

The TickerProvider for the AnimationControllers that run the animations.

Source 

TickerProvider get vsync => _vsync;
void vsync=(TickerProvider value)

Source 

set vsync(TickerProvider value) {
  assert(value != null);
  if (value == _vsync)
    return;
  _vsync = value;
  positionController.resync(vsync);
  reactionController.resync(vsync);
}