Add missing integration with DOM

- Add missing IDL changes to Parent and Child Node mixins from dom spec

- Update `converting nodes into a node` algorithm to enforce trusted types

spec/index.bs

@@ -1476,6 +1476,72 @@ On setting {{SVGAnimatedString/baseVal}}, the following steps are run:
 
 Note: SVG does not have a complete script processing model <a href="https://github.com/w3c/svgwg/issues/196">yet</a>. Trusted Types assumes that the attribute and text body modification protections behave similarly to ones for HTML scripts outlined in [[#enforcement-in-scripts]].
 
+## Integration with DOM ## {#integration-with-dom}
+
+This document modifies the following interfaces defined by [[DOM]]:
+
+<pre class="idl exclude">
+partial interface mixin ParentNode {
+  [CEReactions, Unscopable] undefined prepend((Node or DOMString or TrustedScript)... nodes);
+  [CEReactions, Unscopable] undefined append((Node or DOMString or TrustedScript)... nodes);
+  [CEReactions, Unscopable] undefined replaceChildren((Node or DOMString or TrustedScript)... nodes);
+};
+
+partial interface mixin ChildNode {
+  [CEReactions, Unscopable] undefined before((Node or DOMString or TrustedScript)... nodes);
+  [CEReactions, Unscopable] undefined after((Node or DOMString or TrustedScript)... nodes);
+  [CEReactions, Unscopable] undefined replaceWith((Node or DOMString or TrustedScript)... nodes);
+};
+</pre>
+
+### Node value verification ### {#node-value-verification}
+
+The [=converting nodes into a node=] algorithm is modified as follows:
+
+Given <ins>|parent|,</ins> |nodes| and |document|, run these steps:
+
+1. <ins>Let |isScriptElement| be |parent| is a {{HTMLScriptElement}}.</ins>
+1. <ins>For each |value| in |nodes|:</ins>
+    1. <ins>If |value| is a <a for=/>node</a>, then:</ins>
+        1. <ins>If |isScriptElement| is false, skip to the next |value|.</ins>
+        1. <ins>If |value|'s {{nodeType}} is not {{TEXT_NODE}}, skip to the next |value|.</ins>
+        1. <ins>Let |text| be the result of executing the [$Get Trusted Type compliant string$] algorithm, with the following arguments:</ins>
+            * <ins>{{TrustedScript}} as |expectedType|,</ins>
+            * <ins>|document|'s [=relevant global object=] as |global|,</ins>
+            * <ins>|value|'s <a for=CharacterData>data</a> as |input|,</ins>
+            * <ins>`HTMLScriptElement text` as |sink|,</ins>
+            * <ins>`'script'` as |sinkGroup|.</ins>
+
+            <ins>If the algorithm threw an error, rethrow the error.</ins>
+        1. <ins>Set |value|'s <a for=CharacterData>data</a> to |text|.</ins>
+    1. <ins>If |value| is a string, then:</ins>
+        1. <ins>Let |text| be |value|.</ins>
+        1. <ins>If |isScriptElement| is true:</ins>
+            1. <ins>Let |text| be the result of executing the [$Get Trusted Type compliant string$] algorithm, with the following arguments:</ins>
+                * <ins>{{TrustedScript}} as |expectedType|,</ins>
+                * <ins>|document|'s [=relevant global object=] as |global|,</ins>
+                * <ins>|value| as |input|,</ins>
+                * <ins>`HTMLScriptElement text` as |sink|,</ins>
+                * <ins>`'script'` as |sinkGroup|.</ins>
+
+                <ins>If the algorithm threw an error, rethrow the error.</ins>
+        1. <ins>Let |newValue| be a new {{Text}} <a for=/>node</a> whose
+            <a for=CharacterData>data</a> is |text| and <a for=Node>node document</a> is |document|.</ins>
+        1. <ins>Replace |value| with |newValue|.</ins>
+    1. <ins>If |value| is a {{TrustedScript}}, then:</ins>
+        1. <ins>Let |text| be |value|'s `[[Data]]` internal slot value.</ins>
+        1. <ins>Let |newValue| be a new {{Text}} <a for=/>node</a> whose
+            <a for=CharacterData>data</a> is |text| and <a for=Node>node document</a> is |document|.</ins>
+        1. <ins>Replace |value| with |newValue|.</ins>
+1. Let |node| be null.
+1. <del>Replace each string in |nodes| with a new {{Text}} <a for=/>node</a> whose
+    <a for=CharacterData>data</a> is the string and <a for=Node>node document</a> is |document|.</del>
+1. If |nodes| contains one <a for=/>node</a>, then set |node| to |nodes|[0].
+1. Otherwise, set |node| to a new {{DocumentFragment}} <a for=/>node</a> whose
+    <a for=Node>node document</a> is |document|, and then <a>append</a> each <a for=/>node</a>
+    in |nodes|, if any, to it.
+1. Return |node|.
+
 ## Integration with DOM Parsing ## {#integration-with-dom-parsing}
 
 This document modifies the following interfaces defined by [[DOM-Parsing]]: