Rescan devices later if no device is detected during initialization.

BUG=chrome-os-partner:10000
TEST=Observed device rescans from syslog messages.

Change-Id: I2eaf155e0987a1a228faea23d0dfbc9369aeda2a
Reviewed-on: https://gerrit.chromium.org/gerrit/23872
Tested-by: Ben Chan <benchan@chromium.org>
Reviewed-by: Darin Petkov <petkov@chromium.org>
Commit-Ready: Ben Chan <benchan@chromium.org>
2 files changed