am 3a0146cd: Merge "New API for "immersive" activity windows." into gingerbread

Merge commit '3a0146cd29fae3c5bc29d8d535d67826284f8cc9' into gingerbread-plus-aosp

* commit '3a0146cd29fae3c5bc29d8d535d67826284f8cc9':
  New API for "immersive" activity windows.