am ae66946b: Merge "fix a race in SF buffer management" into gingerbread

Merge commit 'ae66946bd9e9f1168241c75196d2379b43e3ca30' into gingerbread-plus-aosp

* commit 'ae66946bd9e9f1168241c75196d2379b43e3ca30':
  fix a race in SF buffer management