Bug 526394. Back out removal of Composite call.

--HG--
extra : rebase_source : 2836e3c7089690800b46ec2aa2dc8022c5298052

view/src/nsViewManager.cpp

@@ -669,6 +669,7 @@ nsViewManager::UpdateViewAfterScroll(nsView *aView,
     GetViewObserver()->NotifyInvalidateForScrolledView(blit, update);
   }
 
+  Composite();
   --RootViewManager()->mScrollCnt;
 }