factory: Adding a camera preview module.

This CL add a camera preview module provides other test to capture camera's
preview image easily.

BUG=chrome-os-partner:6617
TEST=Manually create a factory test that use the class CameraPreview.

Change-Id: Ib008036b40decb0e40067d91dbda05955bb97b6e
Reviewed-on: https://gerrit.chromium.org/gerrit/19972
Reviewed-by: Tai-Hsu Lin <sheckylin@chromium.org>
Reviewed-by: Chun-Ta Lin <itspeter@chromium.org>
Tested-by: Chun-Ta Lin <itspeter@chromium.org>
Commit-Ready: Chun-Ta Lin <itspeter@chromium.org>
Commit-Ready: Choon Chng <choonc@google.com>
Reviewed-by: Choon Chng <choonc@google.com>
1 file changed