Tests for diff_image.

BUG=chrome-os-partner:12676
TEST=diff_image_unittest.py

Change-Id: I107256fe8667f1d40451611e52463ec792929b32
Reviewed-on: https://gerrit.chromium.org/gerrit/30658
Tested-by: Jon Salz <jsalz@chromium.org>
Reviewed-by: Jon Salz <jsalz@chromium.org>
6 files changed