Support an Event Path API

LayoutTests/fast/dom/shadow/resources/shadow-dom.js

 function createShadowRoot()
 {
     var children = Array.prototype.slice.call(arguments);
     if ((children[0] instanceof Object) && !(children[0] instanceof Node))
         return {'isShadowRoot': true,
                 'attributes': children[0],
                 'children': children.slice(1)};
     return {'isShadowRoot': true,
             'children': children};
 }
@@ skipping 63 matching lines @@
         if (ids[i] != '')
             node = node.getElementById(ids[i]);
     }
     return node;
 }
 
 function dumpNode(node)
 {
     if (!node)
       return 'null';
-    var output = '' + node;
     if (node.id)
-        output += ' id=' + node.id;
-    return output;
+        return '#' + node.id;
+    return '' + node;
+}
+
+function dumpNodeList(nodeList) {
+    var result = "";
+    var length = nodeList.length;
+    for (var i = 0; i < length; i++)
+        result += dumpNode(nodeList[i]) + ", ";
+    result += "length: " + length;
+    return result;
 }
 
 function innermostActiveElement(element)
 {
     element = element || document.activeElement;
     if (isIframeElement(element)) {
         if (element.contentDocument.activeElement)
             return innermostActiveElement(element.contentDocument.activeElement);
         return element;
     }
@@ skipping 58 matching lines @@
 {
     for (var i = 0; i + 1 < elements.length; ++i)
         shouldNavigateFocus(elements[i], elements[i + 1], 'forward');
 }
 
 function testFocusNavigationBackward(elements)
 {
     for (var i = 0; i + 1 < elements.length; ++i)
         shouldNavigateFocus(elements[i], elements[i + 1], 'backward');
 }