Add synchronous mount option to cros-disks.

BUG=chromium-os:16113
TEST=Inserted USB and SD drives to a Cr48 and checked that sync was in the mount flags.

Change-Id: I2107aedfc674b39d1c51b56f7726969f80b52948
Reviewed-on: http://gerrit.chromium.org/gerrit/2102
Reviewed-by: Puneet Kumar <puneetster@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
2 files changed