Как связать свойство Binding.Converter?

Попробуйте

        Actions dragger = new Actions(driver);
        WebElement draggablePartOfScrollbar = driver.findElement(By.xpath("//*[@id='jobreslist_outercontainer']/div/div[2]/div"));

        // drag downwards
        int numberOfPixelsToDragTheScrollbarDown = 50;
        for (int i=10;i<500;i=i+numberOfPixelsToDragTheScrollbarDown){
            try{
        // this causes a gradual drag of the scroll bar, 10 units at a time
        dragger.moveToElement(draggablePartOfScrollbar).clickAndHold().moveByOffset(0,numberOfPixelsToDragTheScrollbarDown).release().perform();
        Thread.sleep(1000L);
            }catch(Exception e1){}
        } 

        // now drag opposite way (downwards)
        numberOfPixelsToDragTheScrollbarDown = -50;
        for (int i=500;i>10;i=i+numberOfPixelsToDragTheScrollbarDown){
        // this causes a gradual drag of the scroll bar, -10 units at a time
        dragger.moveToElement(draggablePartOfScrollbar).clickAndHold().moveByOffset(0,numberOfPixelsToDragTheScrollbarDown).release().perform();
        Thread.sleep(1000L);
        }