Revert of Make ancestors of modal <dialog> inert

Source/core/dom/Node.cpp

Index: Source/core/dom/Node.cpp
diff --git a/Source/core/dom/Node.cpp b/Source/core/dom/Node.cpp
index 5aad79076f8ee71ed4886558bfd2f67a00d4d702..196b9871624da75765208bb0fa70da431c3f9dae 100644
--- a/Source/core/dom/Node.cpp
+++ b/Source/core/dom/Node.cpp
@@ -792,7 +792,7 @@
 bool Node::isInert() const
 {
     const HTMLDialogElement* dialog = document().activeModalDialog();
-    if (dialog && this != document() && !dialog->containsIncludingShadowDOM(this))
+    if (dialog && !containsIncludingShadowDOM(dialog) && !dialog->containsIncludingShadowDOM(this))
         return true;
     return document().ownerElement() && document().ownerElement()->isInert();
 }