Bug 891765 - Don't allow viewManager rootViewDestroy wile Flush. r=roc

view/src/nsViewManager.cpp

@@ -415,8 +415,10 @@ void nsViewManager::ProcessPendingUpdatesForView(nsView* aView,
 #endif
       aView->SetForcedRepaint(false);
       SetPainting(false);
+      FlushDirtyRegionToWidget(aView);
+    } else {
+      FlushDirtyRegionToWidget(aView);
     }
-    FlushDirtyRegionToWidget(aView);
   }
 }