Either content elements or shadow elements should not be treated as insertion points if they are no…

Source/core/dom/shadow/InsertionPoint.cpp

Index: Source/core/dom/shadow/InsertionPoint.cpp
diff --git a/Source/core/dom/shadow/InsertionPoint.cpp b/Source/core/dom/shadow/InsertionPoint.cpp
index a3ee335ebdc4d5e17a59d2b945c22f4f95a52bde..eadd316ca3b3d3ae86ef790b1d3f0353f2dcb310 100644
--- a/Source/core/dom/shadow/InsertionPoint.cpp
+++ b/Source/core/dom/shadow/InsertionPoint.cpp
@@ -143,11 +143,12 @@ bool InsertionPoint::canBeActive() const
 
 bool InsertionPoint::isActive() const
 {
+    if (!inDocument())
+        return false;
     if (!canBeActive())
         return false;
     ShadowRoot* shadowRoot = containingShadowRoot();
-    if (!shadowRoot)
-        return false;
+    ASSERT(shadowRoot);
     if (!hasTagName(shadowTag) || shadowRoot->descendantShadowElementCount() <= 1)
         return true;