Implement DOM: prepend, append, before, after & replaceWith

Source/core/dom/ChildNode.idl

Index: Source/core/dom/ChildNode.idl
diff --git a/Source/core/dom/ChildNode.idl b/Source/core/dom/ChildNode.idl
index 8c2f9f3ac096a566b4af2a8f7ad23645dcfc7512..0b0168ecc06b0ccbdc1d3fed3ecce6d6731fc2fe 100644
--- a/Source/core/dom/ChildNode.idl
+++ b/Source/core/dom/ChildNode.idl
@@ -26,9 +26,8 @@
     LegacyTreatAsPartialInterface,
     NoInterfaceObject, // Always used on target of 'implements'
 ] interface ChildNode {
-    // [Unscopeable] void before((Node or DOMString)... nodes);
-    // [Unscopeable] void after((Node or DOMString)... nodes);
-    // [Unscopeable] void replaceWith((Node or DOMString)... nodes);
-    // TODO(philipj): remove() should be [Unscopeable]. crbug.com/462916
-    [RaisesException, CustomElementCallbacks] void remove();
+    [Unscopeable, RaisesException, CustomElementCallbacks, RuntimeEnabled=DOMConvenienceAPI] void before((Node or DOMString) ... nodes);
+    [Unscopeable, RaisesException, CustomElementCallbacks, RuntimeEnabled=DOMConvenienceAPI] void after((Node or DOMString)... nodes);
+    [Unscopeable, RaisesException, CustomElementCallbacks, RuntimeEnabled=DOMConvenienceAPI] void replaceWith((Node or DOMString)... nodes);
+    [Unscopeable, RaisesException, CustomElementCallbacks] void remove();
 };