am 30f5c8fe: More DropBoxManager javadoc love.

Merge commit '30f5c8fede241e7560f4a33e48af3a4627fd5efc' into gingerbread-plus-aosp

* commit '30f5c8fede241e7560f4a33e48af3a4627fd5efc':
  More DropBoxManager javadoc love.