Bug 1480179 - Fix the traverse() of MediaQueryList in nsDocument, r=smaug

dom/base/nsDocument.cpp

@@ -1959,7 +1959,8 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(nsDocument)
   // methods.
   for (MediaQueryList* mql = tmp->mDOMMediaQueryLists.getFirst(); mql;
        mql = static_cast<LinkedListElement<MediaQueryList>*>(mql)->getNext()) {
-    if (mql->HasListeners()) {
+    if (mql->HasListeners() &&
+        NS_SUCCEEDED(mql->CheckInnerWindowCorrectness())) {
       NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mDOMMediaQueryLists item");
       cb.NoteXPCOMChild(mql);
     }