Rename {Author,UserAgent}ShadowRoot to {Open,Closed}ShadowRoot.

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};
 }
 
-function createUserAgentShadowRoot()
+function createClosedShadowRoot()
 {
     var shadowRoot = createShadowRoot.apply(null, arguments);
-    shadowRoot.isUserAgentShadowRoot = true;
+    shadowRoot.isClosedShadowRoot = true;
     return shadowRoot;
 }
 
 // This function can take optional child elements, which might be a result of createShadowRoot(), as arguments[2:].
 function createDOM(tagName, attributes)
 {
     var element = document.createElement(tagName);
     for (var name in attributes)
         element.setAttribute(name, attributes[name]);
     var childElements = Array.prototype.slice.call(arguments, 2);
     for (var i = 0; i < childElements.length; ++i) {
         var child = childElements[i];
         if (child.isShadowRoot) {
             var shadowRoot;
-            if (child.isUserAgentShadowRoot) {
-                shadowRoot = window.internals.createUserAgentShadowRoot(element);
+            if (child.isClosedShadowRoot) {
+                shadowRoot = window.internals.createClosedShadowRoot(element);
             } else {
                 shadowRoot = element.createShadowRoot();
             }
             if (child.attributes) {
                 for (var attribute in child.attributes) {
                     // Shadow Root does not have setAttribute.
                     shadowRoot[attribute] = child.attributes[attribute];
                 }
             }
             for (var j = 0; j < child.children.length; ++j)
@@ skipping 200 matching lines @@
     debug('Traverse in backward.');
     showComposedShadowTreeByTraversingInBackward(node);
 
     debug('');
 }
 
 function showNextNode(node) {
     var next = internals.nextInComposedTree(node);
     debug('Next node of [' + dumpNode(node) + '] is [' + dumpNode(next) + ']');
 }