am f2f6f8b8: Document that createSocketFileDescriptor throws an exception on failure.

Merge commit 'f2f6f8b8d47733be0f291612730690b5ce379257' into eclair-plus-aosp

* commit 'f2f6f8b8d47733be0f291612730690b5ce379257':
  Document that createSocketFileDescriptor throws an exception on failure.