Disable insertion points in v1 shadow trees.

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];
@@ skipping 46 matching lines @@
         } else
             element.appendChild(child);
     }
     return element;
 }
 
 function convertTemplatesToShadowRootsWithin(node) {
     var nodes = node.querySelectorAll("template");
     for (var i = 0; i < nodes.length; ++i) {
         var template = nodes[i];
-
+        var mode = template.getAttribute("data-mode");
         var parent = template.parentNode;
         parent.removeChild(template);
-        var shadowRoot = parent.createShadowRoot();
+        var shadowRoot;
+        if (!mode) {
+            shadowRoot = parent.createShadowRoot();
+        } else {
+            shadowRoot = parent.attachShadow({'mode': mode});
+        }
         if (template.id)
             shadowRoot.id = template.id;
         var fragments = document.importNode(template.content, true);
         shadowRoot.appendChild(fragments);
 
         convertTemplatesToShadowRootsWithin(shadowRoot);
     }
 }
 
 function isShadowHost(node)
@@ skipping 243 matching lines @@
                 return node;
         }
 
         return null;
     };
 
     if (!window.internals)
         return null;
     return iter(root, id);
 }