What is the purpose of this method in the Silverlight SDK source code?

Question

The following code snippet is from the Silverlight SDK and I am trying to understand the reason it is the way it is. Can anyone explain the need for the for loop?

 internal static DependencyObject GetVisualRoot(DependencyObject d)
        { 
            DependencyObject root = d; 
            for (; ; )
            { 
                FrameworkElement element = root as FrameworkElement;
                if (element == null)
                { 
                    break;
                }

                DependencyObject parent = element.Parent as DependencyObject; 
                if (parent == null)
                { 
                    break;
                }

                root = parent;
            }
            return root; 
        }

Answer 1

It's probably Microsoft style of defining infinite loop.

The loop will traverse through each parent until it failed to cast.

Answer 2

It's walking up the tree looking for any element that is either parentless or not a FrameworkElement. The loop is an unrolled tail recursion. A while(true) loop would have been fine too.