Add Element.attachShadow under the ShadowDOMV1 runtime flag

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

+// TODO(hayato): Have both createShadowRoot and attachShadow.
 function createShadowRoot()
 {
     var children = Array.prototype.slice.call(arguments);
     if ((children[0] instanceof Object) && !(children[0] instanceof Node)) {
         var attributes = {};
         var parameter = {};
         for (var key in children[0]) {
             if (key == 'mode' || key == 'delegatesFocus')
                 parameter[key] = children[0][key];
             else
@@ skipping 23 matching lines @@
         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);
             } else {
                 if (child.parameter && Object.keys(child.parameter).length > 0)
-                    shadowRoot = element.createShadowRoot(child.parameter);
+                    shadowRoot = element.attachShadow(child.parameter);
                 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 235 matching lines @@
 {
     shouldBeEqualToString('backgroundColorOf(\'' + selector + '\')', expected);
 }
 
 function backgroundColorShouldNotBe(selector, color)
 {
     var text = 'backgroundColorOf(\'' + selector + '\')';
     var unevaledString = '"' + color.replace(/\\/g, "\\\\").replace(/"/g, "\"") + '"';
     shouldNotBe(text, unevaledString);
 }