1. @DomName('WebGL2RenderingContext.fenceSync')
  2. @DocsEditable()
  3. @Experimental()
Sync fenceSync(int condition, int flags)

Source 

@DomName('WebGL2RenderingContext.fenceSync')
@DocsEditable()
@Experimental() // untriaged
Sync fenceSync(int condition, int flags) =>
    _blink.BlinkWebGL2RenderingContext.instance
        .fenceSync_Callback_2_(this, condition, flags);