Only pass oldParent to removing steps for the node actually removed

This more accurately represents what browsers actually implement. And
for custom elements we decided we did not need oldParent at all. So
hereby restricting the "insertion steps" and "removing steps" to
avoid accidentally depending on them doing more.

dom.bs

@@ -12,7 +12,7 @@ No Editor: true
 Logo: https://resources.whatwg.org/logo-dom.svg
 Abstract: DOM defines a platform-neutral model for events and node trees.
 Ignored Terms: EmptyString, Array, Document
-Ignored Vars: p, documentFragment, ev, oldParent, em, processingInstruction, obj, tree, removedNode, C, *, intersects, collapsed
+Ignored Vars: p, documentFragment, ev, oldParent, em, processingInstruction, obj, tree, insertedNode, removedNode, C, *, intersects, collapsed
 Boilerplate: omit conformance, omit feedback-header
 </pre>
 
@@ -1535,14 +1535,12 @@ To <dfn export for=Node id=concept-node-pre-insert>pre-insert</dfn> a
 
 <p><a lt="Other applicable specifications">Specifications</a> may define
 <dfn export for=Node id=concept-node-insert-ext>insertion steps</dfn> for all or some <a>nodes</a>.
-The algorithm is passed <var>insertedNode</var> and <var>newAncestor</var> as indicated in the
-<a for=Node>insert</a> algorithm below.
+The algorithm is passed <var>insertedNode</var>, as indicated in the <a for=Node>insert</a>
+algorithm below.
 <!-- See https://github.com/whatwg/dom/issues/34#issuecomment-125571750 for why we might need to
      adjust this further based on the requirements of the script element. There might be other ways
      to define that though as Olli suggests, so leaving that out for now. -->
 
-<p class="note"><var>newAncestor</var> can be <var>insertedNode</var>'s <a>parent</a>.
-
 To <dfn export id=concept-node-insert for=Node>insert</dfn> a <var>node</var>
 into a <var>parent</var> before a <var>child</var>, with an optional
 <i>suppress observers flag</i>, run these steps:
@@ -1600,9 +1598,9 @@ into a <var>parent</var> before a <var>child</var>, with an optional
    <li><p>Insert <var>node</var> into <var>parent</var> before <var>child</var> or at the end of
    <var>parent</var> if <var>child</var> is null.
 
-   <li><p>For each <a>shadow-root-including inclusive descendant</a> <var>descendant</var> of
-   <var>node</var>, in <a>shadow-root-including tree order</a>, run the <a>insertion steps</a> with
-   <var>descendant</var> and <var>parent</var>.
+   <li><p>For each <a>shadow-root-including inclusive descendant</a> <var>inclusiveDescendant</var>
+   of <var>node</var>, in <a>shadow-root-including tree order</a>, run the <a>insertion steps</a>
+   with <var>inclusiveDescendant</var>.
   </ol>
 
  <li>If <i>suppress observers flag</i> is unset,
@@ -1798,10 +1796,8 @@ To <dfn export for=Node id=concept-node-pre-remove>pre-remove</dfn> a
 
 <p><a lt="Other applicable specifications">Specifications</a> may define
 <dfn export for=Node id=concept-node-remove-ext>removing steps</dfn> for all or some <a>nodes</a>.
-The algorithm is passed <var>removedNode</var> and <var>oldAncestor</var>, as indicated in the
-<a>remove</a> algorithm below.
-
-<p class="note"><var>oldAncestor</var> can be <var>removedNode</var>'s former <a>parent</a>.
+The algorithm is passed <var>removedNode</var>, and optionally <var>oldParent</var>, as indicated in
+the <a>remove</a> algorithm below.
 
 To <dfn export for=Node id=concept-node-remove>remove</dfn> a <var>node</var>
 from a <var>parent</var>, with an optional <i>suppress observers flag</i>, run these
@@ -1850,9 +1846,11 @@ steps:
 
  <li>Remove <var>node</var> from its <var>parent</var>.
 
- <li><p>For each <a>shadow-root-including inclusive descendant</a> <var>descendant</var> of
- <var>node</var>, in <a>shadow-root-including tree order</a>, run the <a>removing steps</a> with
- <var>descendant</var> and <var>parent</var>.
+ <li><p>Run the <a>removing steps</a> with <var>node</var> and <var>parent</var>.
+
+ <li><p>For each <a>shadow-root-including descendant</a> <var>descendant</var> of <var>node</var>,
+ in <a>shadow-root-including tree order</a>, run the <a>removing steps</a> with
+ <var>descendant</var>.
 
  <li>For each <a>inclusive ancestor</a> <var>inclusiveAncestor</var> of
  <var>parent</var>, if <var>inclusiveAncestor</var> has any <a>registered observers</a>
@@ -5004,17 +5002,22 @@ interface ShadowRoot : DocumentFragment {
 <dfn export id=concept-shadow-root-including-tree-order>shadow-root-including tree order</dfn>, is
 <a>shadow-root-including preorder, depth-first traversal</a> of a <a>tree</a>.
 <dfn noexport>shadow-root-including preorder, depth-first traversal</dfn> of a <a>tree</a>
-<var>tree</var> is preorder, depth-first traversal of <var>tree</var>, with for each <a>element</a>
-<var>element</var> encountered in <var>tree</var>, whose <a for=Element>shadow root</a> is non-null,
-<a>shadow-root-including preorder, depth-first traversal</a> of the <a>element</a>'s
+<var>tree</var> is preorder, depth-first traversal of <var>tree</var>, with for each
+<a for=/>element</a> <var>element</var> encountered in <var>tree</var>, whose
+<a for=Element>shadow root</a> is non-null,
+<a>shadow-root-including preorder, depth-first traversal</a> of the <a for=/>element</a>'s
 <a for=Element>shadow root</a>'s <a>tree</a> just after it is encountered.
 
 <p>An object <var>A</var> is a
+<dfn export id=concept-shadow-root-including-descendant>shadow-root-including descendant</dfn> of an
+object <var>B</var>, if <var>A</var> is a <a>descendant</a> of <var>B</var>, or <var>A</var>'s
+<a for=tree>root</a> is a <a for=/>shadow root</a> and <var>A</var>'s <a for=tree>root</a>'s
+<a for=DocumentFragment>host</a> is a <a>shadow-root-including inclusive descendant</a> of
+<var>B</var>.
+
+<p>A
 <dfn export id=concept-shadow-root-including-inclusive-descendant>shadow-root-including inclusive descendant</dfn>
-of an object <var>B</var>, if <var>A</var> is an <a>inclusive descendant</a> of <var>B</var>, or
-<var>A</var>'s <a for=tree>root</a> is a <a for=/>shadow root</a> and <var>A</var>'s
-<a for=tree>root</a>'s <a for=DocumentFragment>host</a> is a
-<a>shadow-root-including inclusive descendant</a> of <var>B</var>.
+is an object or one of its <a>shadow-root-including descendants</a>.
 
 <hr>
 

dom.html

@@ -1049,8 +1049,8 @@ <h4 class="heading settled" data-level="4.2.1" id="mutation-algorithms"><span cl
     <li>Return <var>node</var>. 
    </ol>
    <p><a data-link-type="dfn" href="#other-applicable-specifications">Specifications</a> may define <dfn data-dfn-for="Node" data-dfn-type="dfn" data-export="" id="concept-node-insert-ext">insertion steps<a class="self-link" href="#concept-node-insert-ext"></a></dfn> for all or some <a data-link-type="dfn" href="#concept-node">nodes</a>.
-The algorithm is passed <var>insertedNode</var> and <var>newAncestor</var> as indicated in the <a data-link-type="dfn" href="#concept-node-insert">insert</a> algorithm below. </p>
-   <p class="note" role="note"><var>newAncestor</var> can be <var>insertedNode</var>’s <a data-link-type="dfn" href="#concept-tree-parent">parent</a>. </p>
+The algorithm is passed <var>insertedNode</var>, and optionally <var>newParent</var>, as indicated
+in the <a data-link-type="dfn" href="#concept-node-insert">insert</a> algorithm below. </p>
    <p>To <dfn data-dfn-for="Node" data-dfn-type="dfn" data-export="" id="concept-node-insert">insert<a class="self-link" href="#concept-node-insert"></a></dfn> a <var>node</var> into a <var>parent</var> before a <var>child</var>, with an optional <i>suppress observers flag</i>, run these steps:</p>
    <ol>
     <li>Let <var>count</var> be the number of <a data-link-type="dfn" href="#concept-tree-child">children</a> of <var>node</var> if
@@ -1077,7 +1077,10 @@ <h4 class="heading settled" data-level="4.2.1" id="mutation-algorithms"><span cl
       <li>
        <p>Insert <var>node</var> into <var>parent</var> before <var>child</var> or at the end of <var>parent</var> if <var>child</var> is null. </p>
       <li>
-       <p>For each <a data-link-type="dfn" href="#concept-shadow-root-including-inclusive-descendant">shadow-root-including inclusive descendant</a> <var>descendant</var> of <var>node</var>, in <a data-link-type="dfn" href="#concept-shadow-root-including-tree-order">shadow-root-including tree order</a>, run the <a data-link-type="dfn" href="#concept-node-insert-ext">insertion steps</a> with <var>descendant</var> and <var>parent</var>. </p>
+       <p>Run the <a data-link-type="dfn" href="#concept-node-insert-ext">insertion steps</a> with <var>node</var> and <var>parent</var>. </p>
+      <li>
+       <p>For each <a data-link-type="dfn" href="#concept-shadow-root-including-descendant">shadow-root-including descendant</a> <var>descendant</var> of <var>node</var>,
+   in <a data-link-type="dfn" href="#concept-shadow-root-including-tree-order">shadow-root-including tree order</a>, run the <a data-link-type="dfn" href="#concept-node-insert-ext">insertion steps</a> with <var>descendant</var>. </p>
      </ol>
     <li>If <i>suppress observers flag</i> is unset, <a data-link-type="dfn" href="#queue-a-mutation-record">queue a mutation record</a> of "<code>childList</code>" for <var>parent</var> with addedNodes <var>nodes</var>, nextSibling <var>child</var>, and previousSibling <var>child</var>’s <a data-link-type="dfn" href="#concept-tree-previous-sibling">previous sibling</a> or <var>parent</var>’s <a data-link-type="dfn" href="#concept-tree-last-child">last child</a> if <var>child</var> is null. 
    </ol>
@@ -1147,8 +1150,8 @@ <h4 class="heading settled" data-level="4.2.1" id="mutation-algorithms"><span cl
     <li>Return <var>child</var>. 
    </ol>
    <p><a data-link-type="dfn" href="#other-applicable-specifications">Specifications</a> may define <dfn data-dfn-for="Node" data-dfn-type="dfn" data-export="" id="concept-node-remove-ext">removing steps<a class="self-link" href="#concept-node-remove-ext"></a></dfn> for all or some <a data-link-type="dfn" href="#concept-node">nodes</a>.
-The algorithm is passed <var>removedNode</var> and <var>oldAncestor</var>, as indicated in the <a data-link-type="dfn" href="#concept-node-remove">remove</a> algorithm below. </p>
-   <p class="note" role="note"><var>oldAncestor</var> can be <var>removedNode</var>’s former <a data-link-type="dfn" href="#concept-tree-parent">parent</a>. </p>
+The algorithm is passed <var>removedNode</var>, and optionally <var>oldParent</var>, as indicated in
+the <a data-link-type="dfn" href="#concept-node-remove">remove</a> algorithm below. </p>
    <p>To <dfn data-dfn-for="Node" data-dfn-type="dfn" data-export="" id="concept-node-remove">remove<a class="self-link" href="#concept-node-remove"></a></dfn> a <var>node</var> from a <var>parent</var>, with an optional <i>suppress observers flag</i>, run these
 steps:</p>
    <ol>
@@ -1165,7 +1168,10 @@ <h4 class="heading settled" data-level="4.2.1" id="mutation-algorithms"><span cl
     <li>Let <var>oldNextSibling</var> be <var>node</var>’s <a data-link-type="dfn" href="#concept-tree-next-sibling">next sibling</a>. 
     <li>Remove <var>node</var> from its <var>parent</var>. 
     <li>
-     <p>For each <a data-link-type="dfn" href="#concept-shadow-root-including-inclusive-descendant">shadow-root-including inclusive descendant</a> <var>descendant</var> of <var>node</var>, in <a data-link-type="dfn" href="#concept-shadow-root-including-tree-order">shadow-root-including tree order</a>, run the <a data-link-type="dfn" href="#concept-node-remove-ext">removing steps</a> with <var>descendant</var> and <var>parent</var>. </p>
+     <p>Run the <a data-link-type="dfn" href="#concept-node-remove-ext">removing steps</a> with <var>node</var> and <var>parent</var>. </p>
+    <li>
+     <p>For each <a data-link-type="dfn" href="#concept-shadow-root-including-descendant">shadow-root-including descendant</a> <var>descendant</var> of <var>node</var>,
+ in <a data-link-type="dfn" href="#concept-shadow-root-including-tree-order">shadow-root-including tree order</a>, run the <a data-link-type="dfn" href="#concept-node-remove-ext">removing steps</a> with <var>descendant</var>. </p>
     <li>For each <a data-link-type="dfn" href="#concept-tree-inclusive-ancestor">inclusive ancestor</a> <var>inclusiveAncestor</var> of <var>parent</var>, if <var>inclusiveAncestor</var> has any <a data-link-type="dfn" href="#registered-observer">registered observers</a> whose <b>options</b>' <code class="idl"><a data-link-type="idl" href="#dom-mutationobserverinit-subtree">subtree</a></code> is true, then for each
  such <a data-link-type="dfn" href="#registered-observer">registered observer</a> <var>registered</var>, append a <a data-link-type="dfn" href="#transient-registered-observer">transient registered observer</a> whose <b>observer</b> and <b>options</b> are identical to those of <var>registered</var> and <b>source</b> which is <var>registered</var> to <var>node</var>’s list of <a data-link-type="dfn" href="#registered-observer">registered observers</a>. 
     <li>If <i>suppress observers flag</i> is unset, <a data-link-type="dfn" href="#queue-a-mutation-record">queue a mutation record</a> of "<code>childList</code>" for <var>parent</var> with removedNodes a list solely containing <var>node</var>,
@@ -2779,7 +2785,8 @@ <h3 class="heading settled" data-level="4.8" id="interface-shadowroot"><span cla
    <p>The <dfn class="idl-code" data-dfn-for="ShadowRoot" data-dfn-type="attribute" data-export="" id="dom-shadowroot-host"><code>host</code><a class="self-link" href="#dom-shadowroot-host"></a></dfn> attribute’s getter must return the <a data-link-type="dfn" href="#context-object">context object</a>’s <a data-link-type="dfn" href="#concept-documentfragment-host">host</a>. </p>
    <hr>
    <p>In <dfn data-dfn-type="dfn" data-export="" id="concept-shadow-root-including-tree-order">shadow-root-including tree order<a class="self-link" href="#concept-shadow-root-including-tree-order"></a></dfn>, is <a data-link-type="dfn" href="#shadow-root-including-preorder-depth-first-traversal">shadow-root-including preorder, depth-first traversal</a> of a <a data-link-type="dfn" href="#concept-tree">tree</a>. <dfn data-dfn-type="dfn" data-noexport="" id="shadow-root-including-preorder-depth-first-traversal">shadow-root-including preorder, depth-first traversal<a class="self-link" href="#shadow-root-including-preorder-depth-first-traversal"></a></dfn> of a <a data-link-type="dfn" href="#concept-tree">tree</a> <var>tree</var> is preorder, depth-first traversal of <var>tree</var>, with for each <a data-link-type="dfn" href="#concept-element">element</a> <var>element</var> encountered in <var>tree</var>, whose <a data-link-type="dfn" href="#concept-element-shadow-root">shadow root</a> is non-null, <a data-link-type="dfn" href="#shadow-root-including-preorder-depth-first-traversal">shadow-root-including preorder, depth-first traversal</a> of the <a data-link-type="dfn" href="#concept-element">element</a>’s <a data-link-type="dfn" href="#concept-element-shadow-root">shadow root</a>’s <a data-link-type="dfn" href="#concept-tree">tree</a> just after it is encountered. </p>
-   <p>An object <var>A</var> is a <dfn data-dfn-type="dfn" data-export="" id="concept-shadow-root-including-inclusive-descendant">shadow-root-including inclusive descendant<a class="self-link" href="#concept-shadow-root-including-inclusive-descendant"></a></dfn> of an object <var>B</var>, if <var>A</var> is an <a data-link-type="dfn" href="#concept-tree-inclusive-descendant">inclusive descendant</a> of <var>B</var>, or <var>A</var>’s <a data-link-type="dfn" href="#concept-tree-root">root</a> is a <a data-link-type="dfn" href="#concept-shadow-root">shadow root</a> and <var>A</var>’s <a data-link-type="dfn" href="#concept-tree-root">root</a>’s <a data-link-type="dfn" href="#concept-documentfragment-host">host</a> is a <a data-link-type="dfn" href="#concept-shadow-root-including-inclusive-descendant">shadow-root-including inclusive descendant</a> of <var>B</var>. </p>
+   <p>An object <var>A</var> is a <dfn data-dfn-type="dfn" data-export="" id="concept-shadow-root-including-descendant">shadow-root-including descendant<a class="self-link" href="#concept-shadow-root-including-descendant"></a></dfn> of an
+object <var>B</var>, if <var>A</var> is a <a data-link-type="dfn" href="#concept-tree-descendant">descendant</a> of <var>B</var>, or <var>A</var>’s <a data-link-type="dfn" href="#concept-tree-root">root</a> is a <a data-link-type="dfn" href="#concept-shadow-root">shadow root</a> and <var>A</var>’s <a data-link-type="dfn" href="#concept-tree-root">root</a>’s <a data-link-type="dfn" href="#concept-documentfragment-host">host</a> is <var>B</var> or a <a data-link-type="dfn" href="#concept-shadow-root-including-descendant">shadow-root-including descendant</a> of <var>B</var>. </p>
    <hr>
    <p class="XXX">For now you can find more information about this object in <a href="https://w3c.github.io/webcomponents/spec/shadow/">Shadow DOM</a>. The DOM Standard will be
 updated over time to cover more details. </p>
@@ -5463,7 +5470,7 @@ <h3 class="no-num no-ref heading settled" id="index-defined-here"><span class="c
      <li><a href="#concept-element-shadow-root">dfn for Element</a><span>, in §4.9</span>
     </ul>
    <li><a href="#dom-element-shadowroot">shadowRoot</a><span>, in §4.9</span>
-   <li><a href="#concept-shadow-root-including-inclusive-descendant">shadow-root-including inclusive descendant</a><span>, in §4.8</span>
+   <li><a href="#concept-shadow-root-including-descendant">shadow-root-including descendant</a><span>, in §4.8</span>
    <li><a href="#shadow-root-including-preorder-depth-first-traversal">shadow-root-including preorder, depth-first traversal</a><span>, in §4.8</span>
    <li><a href="#concept-shadow-root-including-tree-order">shadow-root-including tree order</a><span>, in §4.8</span>
    <li><a href="#dictdef-shadowrootinit">ShadowRootInit</a><span>, in §4.9</span>