Backed out changeset 07c23fd98229 (bug 1489437) for multiple failures in nsHtml5DocumentBuilder

parser/html/nsHtml5TreeOperation.cpp

@@ -178,8 +178,6 @@ nsHtml5TreeOperation::Append(nsIContent* aNode,
   MOZ_ASSERT(aBuilder->IsInDocUpdate());
   nsresult rv = NS_OK;
   nsHtml5OtherDocUpdate update(aParent->OwnerDoc(), aBuilder->GetDocument());
-  dom::AutoCEReaction autoCEReaction(
-    aParent->OwnerDoc()->GetDocGroup()->CustomElementReactionsStack(), nullptr);
   rv = aParent->AppendChildTo(aNode, false);
   if (NS_SUCCEEDED(rv)) {
     aNode->SetParserHasNotified();

testing/web-platform/meta/custom-elements/parser/parser-sets-attributes-and-children.html.ini

@@ -0,0 +1,4 @@
+[parser-sets-attributes-and-children.html]
+  [HTML parser should call connectedCallback before appending child nodes.]
+    expected: FAIL
+