Bug 664463 - Don't load anything to frameloader if it isn't in the docshell tree anymore, r=bz

content/base/src/nsFrameLoader.cpp

@@ -1405,6 +1405,7 @@ nsFrameLoader::MaybeCreateDocShell()
   nsCOMPtr<nsISupports> container =
     doc->GetContainer();
   nsCOMPtr<nsIWebNavigation> parentAsWebNav = do_QueryInterface(container);
+  NS_ENSURE_STATE(parentAsWebNav);
 
   // Create the docshell...
   mDocShell = do_CreateInstance("@mozilla.org/docshell;1");
@@ -1457,6 +1458,7 @@ nsFrameLoader::MaybeCreateDocShell()
     // this some other way.....  Not sure how yet.
     nsCOMPtr<nsIDocShellTreeOwner> parentTreeOwner;
     parentAsItem->GetTreeOwner(getter_AddRefs(parentTreeOwner));
+    NS_ENSURE_STATE(parentTreeOwner);
     mIsTopLevelContent =
       AddTreeItemToTreeOwner(docShellAsItem, mOwnerContent, parentTreeOwner,
                              parentType, parentAsNode);