Bug 573127. Adjust the assert slightly to make it match reality. r=dbaron

layout/base/RestyleTracker.cpp

@@ -108,7 +108,8 @@ CollectRestyles(nsISupports* aElement,
   NS_ASSERTION(!element->HasFlag(collector->tracker->RootBit()) ||
                // Maybe we're just not reachable via the frame tree?
                (element->GetFlattenedTreeParent() &&
-                !element->GetFlattenedTreeParent()->GetPrimaryFrame()) ||
+                (!element->GetFlattenedTreeParent()->GetPrimaryFrame()||
+                 element->GetFlattenedTreeParent()->GetPrimaryFrame()->IsLeaf())) ||
                // Or not reachable due to an async reinsert we have
                // pending?  If so, we'll have a reframe hint around.
                // That incidentally makes it safe that we still have