1. DomName('WebGL2RenderingContext.waitSync')
  2. DocsEditable()
  3. Experimental()
void waitSync(Sync sync, int flags, int timeout)

Source 

@DomName('WebGL2RenderingContext.waitSync')
@DocsEditable()
@Experimental() // untriaged
void waitSync(Sync sync, int flags, int timeout) => _blink.BlinkWebGL2RenderingContext.instance.waitSync_Callback_3_(this, sync, flags, timeout);