Changes grit_info.py to respect target_platform when generating output lists.

Patch from issue 22923027, by rohitrao@chromium.org

Review URL: https://codereview.chromium.org/23102022

git-svn-id: http://grit-i18n.googlecode.com/svn/trunk@134 7262f16d-afe8-6277-6482-052fa10e57b1